Authors:Guo-long Guo, Ming-biao Luo, Jing-jing Xu, Teng-xiang Wang, Rong Hua and Yu-zhen Sun
A method for continuous determination of the light rare earth elements (LREEs) and thorium in Baotou Iron Ore was established.
The light rare earths and thorium were adsorbed on a micro-column packed with HD-8 cation exchange resins. The light rare
earth elements were eluted with 4 mol L−1 HCl–2 mol L−1 NH4Cl solution and determined with tribromo-arsenzao by a 721-E spectrophotometry at 630 nm; thorium was eluted with 5% potassium
oxalate solution and determined with Arsenazo III by a 721-E spectrophotometry at 660 nm. The measured values by the proposed
method were in close agreement with the certified values (Baotou main ore standard sample, Baotou ore R-715 standard sample
and GSD-2 standard sample). The RSD of the light rare earths and thorium in Baotou Iron Ore were of <1.70% and <1.99%, respectively.
Authors:Xiang-Rong Xu, Fu-Qing Tan, Jun-Quan Zhu, Ting Ye, Chun-Lin Wang, Yi-Feng Zhu, Hans-Uwe Dahms, Fan Jin and Wan-Xi Yang
We used single-cell gel electrophoresis (SCGE) to detect the integrity of sperm DNA of the teleost large yellow croaker, Pseudosciaena crocea, cryopreserved with Cortland solution and a range of 5% to 30% DMSO concentrations in order to test how sperm cryopreservation affected the DNA stability of nuclei. Electrophoresis was conducted for 60 min at 130 mA and 15 V. The comet images were analyzed with software CometScore 1.5, and parameters such as comet length, tail length and percentage DNA in the tail were obtained. Then the comet rate and damage coefficient were calculated. Results demonstrated that there were no significant differences in motility, comet rate and damage coefficient between fresh sperm and cryopreserved sperm stored in 5%, 10%, 15% and 20% DMSO, while the sperm cryopreserved with 25% and 30% DMSO had a lower motility, higher comet length and damage coefficients than those of fresh sperm. There was a positive correlation between comet rate of cryopreserved sperm and the concentration of DMSO. Our results demonstrate that toxicity of the cryoprotectant is the main cause of DNA damage in cryopreserved sperm nuclei.