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The Effect of N-Acetylcysteine Addition on the Polymerization Behavior of PMMA Bone Cement
Yanping Cheng,임범순,양형철,조재형,이상혁 한국고분자학회 2012 Macromolecular Research Vol.20 No.9
N-Acetylcysteine (NAC), a well-known thiol-containing antioxidant, may alleviate the toxicity of poly (methyl methacrylate) (PMMA) bone cement through the inactivation of the monomer components in the cement by its sulfhydryl moiety. This study aimed to reveal the effects of the NAC on the polymerization heat, degree of conversion (DC), mechanical properties, and residual monomer release of PMMA bone cement. The addition of NAC (0, 0.25, 0.50, 0.75, and 1.00 wt%) to PMMA powder significantly reduced the maximum polymerization temperature and steadily delayed the setting time. The DC of all experimental PMMA bone cements reached as high as 91% after 7 days of incubation, as determined by Fourier transform infrared spectroscopy (FTIR). The experimental groups showed steady declines in flexural strength and surface hardness as a fraction of increasing NAC. Meanwhile,the mechanical properties of the experimental groups increased with the duration of time. The amount of methyl methacrylate (MMA) leached into deionized water was analyzed using high performance liquid chromatography (HPLC) and was found to increase with an immersion time up to 24 h, after which no subsequent change was observed. The results showed a linear correlation between the thermal and mechanical properties and the released MMA with the DCs of the experimental groups. The potential usefulness of NAC in developing more biocompatible PMMA bone cement for increased working performance was highlighted in this study.
Yanping Wang,Qiaoling Cheng,Zaheer Ahmed,Xiaoxue Jiang,Xiaojia Bai 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.5
Glutinous rice wine mash liquor is a traditional food of south of China and its ability to coagulate the milk has been proved. The aim of this work was to extract milk-clotting enzyme from glutinous rice wine mash liquor. A partial purified extract of enzyme was obtained by fractional precipitation with (NH4)2SO4. The fractions obtained by precipitation, 40-90% possessed the milk-clotting activity (MCA) (145.72 U/mg). The 40-90% (NH4)2SO4 fraction was further purified by sephadex G-100 and DEAE-sephadex A-50 with MCA (4,360±50 U/mg), which was confirmed by SDS-PAGE that showed only one band with a molecular mass of 36.0 kDa. Highest MCA was attained at 36℃. The enzyme was completely inactivated by heating for 20 min at 60℃. The MCA increased with the decreasing of milk pH from 8.0 to 5.5, and it was active at the wide range of pH 1 to 7. The metal ions Mg2+, Ca2+, Ba2+, Mn2+, Al3+, Fe2+ had a very clear function to accelerate milk coagulation whereas Na+ and K+ decelerated the activity slightly. The curd effect of the milk-clotting enzyme has primarily been studied.
Genome-wide association study for intramuscular fat content in Chinese Lulai black pigs
Yanping Wang,Chao Ning,Cheng Wang,Jianfeng Guo,Jiying Wang,Ying Wu 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.5
Objective: Intramuscular fat (IMF) content plays an important role in meat quality. Identification of single nucleotide polymorphisms (SNPs) and genes related to pig IMF, especially using pig populations with high IMF content variation, can help to establish novel molecular breeding tools for optimizing IMF in pork and unveil the mechanisms that underlie fat metabolism. Methods: We collected muscle samples of 453 Chinese Lulai black pigs, measured IMF content by Soxhlet petroleum-ether extraction method, and genotyped genome-wide SNPs using GeneSeek Genomic Profiler Porcine HD BeadChip. Then a genome-wide association study was performed using a linear mixed model implemented in the GEMMA software. Results: A total of 43 SNPs were identified to be significantly associated with IMF content by the cutoff p<0.001. Among these significant SNPs, the greatest number of SNPs (n = 19) were detected on Chr.9, and two linkage disequilibrium blocks were formed among them. Additionally, 17 significant SNPs are mapped to previously reported quantitative trait loci (QTLs) of IMF and confirmed previous QTLs studies. Forty-two annotated genes centering these significant SNPs were obtained from Ensembl database. Overrepresentation test of pathways and gene ontology (GO) terms revealed some enriched reactome pathways and GO terms, which mainly involved regulation of basic material transport, energy metabolic process and signaling pathway. Conclusion: These findings improve our understanding of the genetic architecture of IMF content in pork and facilitate the follow-up study of fine-mapping genes that influence fat deposition in muscle.
Wang, Yanping,Zhao, Xueyan,Wang, Cheng,Wang, Wenwen,Zhang, Qin,Wu, Ying,Wang, Jiying Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.7
Objective: Shandong indigenous pig breeds are important Chinese pig resources. Their progressive population decline in recent decades has attracted attention towards their conservation. Conservation genetics of these indigenous breeds are essential for developing a conservation and utilization scheme. Methods: A high-density single nucleotide polymorphism (HD-SNP) chip-based comparative analysis of genetic characteristics was performed for seven Shandong indigenous pig breeds in the context of five Western commercial breeds. Results: The results showed that Shandong indigenous pig breeds varied greatly in genetic diversity, effective population size, inbreeding level, and genetic distance with the Western commercial breeds. Specifically, Laiwu and Dapulian displayed low genetic diversity, and had a genetically distant relationship with the Western commercial breeds (average F statistics [F<sub>ST</sub>] value of 0.3226 and 0.2666, respectively). Contrastingly, the other five breeds (Yantai, Licha, Yimeng, Wulain, and Heigai) displayed high genetic diversity within breed and had some extent of mixture pattern with the Western commercial breeds, especially Duroc and Landrace (F<sub>ST</sub> values from 0.1043 to 0.2536). Furthermore, intensive gene flow was discovered among the seven Shandong indigenous breeds, particularly Wulian, Licha, and Heigai, as indicated by the large cluster formed in the principal component analysis scatterplot and small population differentiation (average of 0.1253) among them. Conclusion: Our study advances the understanding of genetic characteristics of Shandong indigenous breeds and provides essential information for developing an appropriate conservation and utilization scheme for these breeds.
Yujie Zhang,Xu Zhang,Nini Cheng,Yanping Li,Jinyi Xing 한국유전학회 2015 Genes & Genomics Vol.37 No.7
Identification of essential fragments in the promoter region of genes to drive tissue-specific expression of exogenous genes in the skeletal muscle is obligatory for animal transgenic study. The skeletal a-actin is a major protein of the thin filaments of skeletal muscle fiber. In this study, the specificity and activity of porcine skeletal aactin gene promoter were investigated by approaches of cell transfection and assayed with green fluorescent protein (GFP) and dual luciferase reporter activity, respectively. The results revealed that the obtained 3717 bp fragment of porcine skeletal a-actin gene promoter drives GFP to be expressed uniquely in murine C2C12 cells, and two segments of 2.0–2.3 and 0.06–0.37 kb in the promoter region were essential for porcine skeletal a-actin gene expression. The regulatory elements in the 0.06–0.37 kb fragment were further investigated, and when it is deleted or the CArG box within this fragment was mutated, the promoter activity was reduced to 20 or 43 % (P\0.01), respectively, compared to the 3.04 kb segment, suggesting an important role of CArG box in regulating porcine skeletal a-actin gene transcription. The results may provide reference for creating transgenic pigs to express exogenous genes uniquely in pork.