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Sui, Shiyan,Jia, Yimin,He, Bin,Li, Runsheng,Li, Xian,Cai, Demin,Song, Haogang,Zhang, Rongkui,Zhao, Ruqian Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.12
Maternal malnutrition during pregnancy may give rise to female offspring with disrupted ovary functions in adult age. Neonatal ovary development predisposes adult ovary function, yet the effect of maternal nutrition on the neonatal ovary has not been described. Therefore, here we show the impact of maternal protein restriction on the expression of folliculogenic and steroidogenic genes, their regulatory microRNAs and promoter DNA methylation in the ovary of neonatal piglets. Sows were fed either standard-protein (SP, 15% crude protein) or low-protein (LP, 7.5% crude protein) diets throughout gestation. Female piglets born to LP sows showed significantly decreased ovary weight relative to body weight (p<0.05) at birth, which was accompanied with an increased serum estradiol level (p<0.05). The LP piglets demonstrated higher ratio of bcl-2 associated X protein/B cell lymphoma/leukemia-2 mRNA (p<0.01), which was associated with up-regulated mRNA expression of bone morphogenic protein 4 (BMP4) (p<0.05) and proliferating cell nuclear antigen (PCNA) (p<0.05). The steroidogenic gene, cytochrome P450 aromatase (CYP19A1) was significantly down-regulated (p<0.05) in LP piglets. The alterations in ovarian gene expression were associated with a significant down-regulation of follicle-stimulating hormone receptor mRNA expression (p<0.05) in LP piglets. Moreover, three microRNAs, including miR-423-5p targeting both CYP19A1 and PCNA, miR-378 targeting CYP19A1 and miR-210 targeting BMP4, were significantly down-regulated (p<0.05) in the ovary of LP piglets. These results suggest that microRNAs are involved in mediating the effect of maternal protein restriction on ovarian function through regulating the expression of folliculogenic and steroidogenic genes in newborn piglets.
Synthesis and Characterization of Low Viscosity Aromatic Hyperbranched Polyester Epoxy Resin
Zhang, Daohong,Jia, Demin,Zhou, Zihu The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.5
Low viscosity aromatic hyperbranched polyester epoxy resin (HTBE) was synthesized by the reaction between epichlorohydrin (ECH) and carboxyl-end hyperbranched polyester (HTB) which was prepared from inexpensive materials $A_2$ (1,4-butanediol glycol, BEG) and $B_3$ (trimellitic anhydride, TMA) by pseudo one-step method. The molar mass of the HTB was calculated from its acid value by "Recursive Probability Approach". The degree of branching (DB) of the HTB was characterized by model compounds and $^1H$ NMR-minus spectrum technology, and the DB of the HTB was about $0.47{\sim}0.63$. The viscosity and epoxy equivalent weight of the HTBE were $3,600{\sim}5,000\;cp$ and lower than 540 g/mol respectively. The reaction mechanism and structure of the $AB_2$ monomer, HTB and HTBE were investigated by MS, $^1H$ NMR and FTIR spectra technology. The molecular size of HTBE is under 8.65 nm and its shape is ellipsoid-like as determined by molecular simulation.
Simin Li,Yuanfang Luo,Chen Yongjun,Tiwen Xu,Bangchao Zhong,Zhixin Jia,Demin Jia 한국섬유공학회 2019 Fibers and polymers Vol.20 No.8
To simultaneously improve processing performances of rubber composites and avoid additive-blooming problem,the concept of “supported rubber additives” was introduced and reactive processing additive oleic acid (OA) was chemicallyimmobilized onto the surface of silica to obtain silica-supported processing additive (SiO2-s-OA). In this study, SiO2-s-OAwas uniformly dispersed into styrene-butadiene rubber (SBR) and gained improved interfacial interaction with rubber matrixdue to its good compatibility and the reaction during vulcanization. Consequently, SBR compounds with SiO2-s-OApossessed lower vulcanizing torque and viscosity under high shear frequency, showing improved processing performance. Moreover, the tensile modulus and strength of SBR/SiO2-s-OA could be enhanced by as much as 88.40 % and 11.44 %compared to SBR/SiO2, respectively, which is also higher than SBR/m-SiO2. Taken together, these results indicate that thismethod for the surface treatment of silica to prepare supported rubber additives may be extended for other nanofillers andrubber additives, which has better processing performance and improved mechanical property simultaneously.