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To investigate the contamination levels of heavy metals, surface water and sediment samples were collected from 21 sites along the Gan River. The heavy metal concentrations (V, Co, Cr, Ni, Cu, Zn, Cd, and Pb) were determined using inductively coupled plasma spectrometry (ICP-MS). The results demonstrated that the status of the surface water and sediments as a whole were relatively clean with regard to heavy metals (except for Cd) compared to water quality standards and sediment quality guidelines. The two heavy metal sources of the surface water and sediments were identified separately using factor analysis (FA). High levels of metals were found in the sediment in the upstream and downstream due to frequent mining and industrial activities, whereas concentrations of heavy metal in the surface water from two sources were abundant in the upstream and midstream – likely related to mining activities and sediment suspension. As indicated by enrichment factor (EF) and potential ecological risk index (PERI), Zn, Pb, and Cd were the most anthropogenically enriched metals, while sediments in the upstream and downstream had high potential ecological risk. Local people, including adults and children who ingested water from the Gan River, showed little potential non-carcinogenic risk, as the hazard index (HI) scores were less than 1. Compared with those in other rivers in the world, heavy metal enrichments in surface water and sediments were of moderate levels.
Somatic cell nuclear transfer (SCNT) is currently the most efficient and precise method to generate genetically tailored pig models for both agricultural and biomedical research. However, its efficiency is crucially dependent on the source of nuclear donor cells. In this study, we compared the cloning efficiency by using three lines of donor cells that are derived from fetal, newborn and adult fibroblasts of Chinese indigenous Meishan pig. We showed that cleavage rate and blastocyst formation rate of the reconstructed embryos were not significantly different between the fetal (80.7% and 15.6%) and newborn ear skin (77.5% and 12.3%) fibroblast groups (p>0.05), but in both groups these indices were significantly higher than that found in the adult ear skin (70.5% and 8.8%; p<0.05). Reconstructed embryos derived from fetal, newborn, and adult ear skin fibroblasts were transferred to four surrogates, respectively. For the fetal, newborn, and adult ear skin fibroblasts, the number of pregnancies were two (50.0%), two (50.0%), and one (25.0%), respectively, and the number of deliveries were two (50.0%), one (25.0%), and zero (0.0%), respectively. Seven and two cloned piglets were obtained from the fetal and newborn ear skin fibroblasts respectively, while no piglets were obtained from the adult ear skin fibroblasts. Two cloned piglets from the newborn ear skin fibroblasts died shortly after birth because of neonatal asphyxia caused by dystocia. The birth weights of the piglets derived from the fetal and newborn ear skin fibroblasts were 1230.5 and 1310.0g, respectively, which were statistically insignificant (p>0.05), but both were significantly higher than that of the control groups (p<0.05). Microsatellite analyses demonstrated that the genotypes of all cloned piglets were identical to their donor cells. Therefore, cloned pigs were successfully produced using two sources of donor cells isolated from the fetal and newborn ear skin fibroblasts of Meishan piglet, and indicating a better cloning efficiency than that obtained from adult fibroblasts. We concluded that the nuclear donor cell lines have significant impact on the developmental competence of cloned embryos as well as on the cloning efficiency of Meishan pig.
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