Laser Melting of Prefabrication AlOOH-Activated Film on the Surface of Nodular Cast Iron and Its Associated Properties.

This study aimed to improve the absorption rate of laser energy on the surface of nodular cast iron and further improve its thermal stability and wear resistance. After a 0.3 mm thick AlOOH activation film was pre-sprayed onto the polished surface of the nodular cast iron, a GWLASER 6 kw fiber laser cladding system was used to prepare a mixed dense oxide layer mainly composed of Al2O3, Fe3O4, and SiO2 using the optimal laser melting parameters of 470 W (laser power) and 5.5 mm/s (scanning speed). By comparing and characterizing the prefabricated laser-melted surface, the laser-remelted surface with the same parameters, and the substrate surface, it was found that there was little difference in the structure, composition, and performance between the laser-remelted surface and the substrate surface except for the morphology. The morphology, structure, and performance of the laser-melted surface underwent significant changes, with a stable surface line roughness of 0.9 µm and a 300-400 µm deep heat-affected zone. It could undergo two 1100 °C thermal shock cycles; its average microhardness increased by more than one compared to the remelted and substrate surfaces of 300 HV, with a maximum hardness of 900 HV; and the average friction coefficient and wear quantity decreased to 0.4370 and 0.001 g, respectively. The prefabricated activated film layer greatly improved the thermal stability and wear resistance of the nodular cast iron surface while reducing the laser melting power.

Expression of CPEB1 gene affects the cycle of ovarian granulosa cells from adult and young goats

Background: CPEB is considered as an RNA-binding protein first identified in Xenopus oocytes. Although CPEB1 was involved in the growth of oocyte, its role in goat follicular granulosa cell has not been fully elucidated. To clarify the functions of this gene in goat follicular granulosa cells, CPEB1-overexpressing vector and interference vector were structured and transfected into follicular granulosa cells from Jiangsu native white goats of Nantong city, Jiangsu Province, China. The expression levels of differentiation-related genes including CDK1, Cyclin B1, and C-mos were determined 24 h after administration of CPEB1 by quantitative real-time polymerase chain reaction and Western blotting methods. Results: The expression levels of CDK1, Cyclin B1, and C-mos were significantly upregulated after overexpression and significantly downregulated after interference with CPEB1. Conclusions: The CPEB1 gene expression could affect the transcription of genes related to early cleavage divisions, which provided a reference for further research on its role in the growth and maturation of oocytes.

Hair follicle stem cells isolated from newborn Yangtze River Delta White Goats.

Adult stem cells are self-renewing populations that originate from embryonic progenitor cells during organogenesis and retain multipotency to support tissue and organ regeneration throughout the lifetime of an organism. The hair follicle (HF) is a small organ that is ideal for studying the biology and regulation of adult stem cells. A distinct, permanent pool of adult stem cells is located in the HF bulge region. Most methods used to isolate hair follicle stem cells (HFSCs) begin with mouse or human follicles. Here, we describe two methods of isolating HFSCs from newborn Yangtze River Delta White Goats. A suitable method was found. The cell viability and expression of HFSC marker proteins differed in the two methods. CD49f-positive (integrin alpha 6) HFSCs were sorted by fluorescence activated flow cytometry. Sorted HFSCs can be used in various in vivo grafting models and are useful as an in vitro model to study multipotency, quiescence and activation.

Methylation analysis of CMTM3 and DUSP1 gene promoters in high-quality brush hair in the Yangtze River delta white goat.

The Yangtze River delta white goat is the only goat breed that produces high-quality brush hair, which is specifically used in top-grade writing brushes. Previous studies have indicated that the CMTM3 and DUSP1 genes are involved in the growth and cycle of high-quality brush hair, and these genes are thought to be involved in the formation of high-quality brush hair traits. In this study, we investigated the relationship between methylation of CMTM3 and DUSP1 and such traits. The results indicated that the relative expression levels of the CMTM3 and DUSP1 genes were higher in non-high-quality brush hair than in high-quality brush hair. Furthermore, the CpG sites of the DUSP1 gene were not methylated, and the methylation level of CMTM3 was negatively correlated with the gene expression level. We believe that the DUSP1 gene regulates the formation of high-quality brush hair by non-methylated, and that methylation of the CMTM3 gene results in a decrease in its expression, causing an increase in the activity of the androgen receptor and the level of androgen. This high androgen level promotes the growth of high-quality brush hair. These study results provide a theoretical basis for further elucidating the molecular mechanism of the formation of high-quality brush hair characteristics, and provide scientific reference for the molecular breeding of high-quality brush hair.

Overexpression of CDC25C affects the cell cycle of ovarian granulosa cells from adult and young goats

Background: CDC25 is a dual-specificity phosphatase that was first identified in the yeast Schizosaccharomyces pombe as a cell cycle-defective mutant. Although CDC25 is involved in the cell cycle of ovarian granulosa cells, the CDC25 signaling pathway has not been clarified fully. To explore the role of CDC25C in the cell cycle of goat ovarian granulosa cells, a CDC25C-overexpressing vector, pCMV-HA-CDC25C, was constructed and transfected into granulosa cells from adult and young white goats from Jiangsu Nantong. RT-PCR was used to measure CDC25C, CDK1, and WEE1 gene expression levels, and flow cytometry was used to distinguish ovarian granulosa cells in different phases of the cell cycle. Progesterone and estradiol levels in transfected ovarian granulosa cells were also measured. Results: In adult goat follicular granulosa cells transfected with pCMV-HA-CDC25C, CDC25C expression increased significantly, which greatly increased the relative gene expression levels of both CDK1 and WEE1. Additionally, progesterone and estradiol levels were increased in goat follicular granulosa cells overexpressing CDC25C. And the cell cycle results showed that transfection of pCMV-HA-CDC25C leads to a higher proportion of cells in S phase compared to the no vector-transfected groups. Conclusions: The results of this study indicated that the overexpression of CDC25C may increase the gene expression levels of both WEE1 and CDK1 in S phase and accelerate the transition of cells from G1 phase to S phase.