ABSTRACT
Objective To explore the feasibility of using portable γ spectrometer to rapidly identify the low activity of depleted uranium and the underlying conditions.Methods Firstly,high purity germanium (Ge) γ spectrometer was used to analyze energy spectrum of DU samples (5 g) and calculate nuclide percentage of 235U in an attempt to ascertain the properties of these DU samples.The portable γ spectrometer was used to provide the evidences for identification of DU samples.Secondly,portable γ spectrometer was also used to identify DU samples of same group.These samples contain 1 g DU powder and 0-5 g environmental clay powder,which were sealed with double layer pocket,and then detected with a distance of 1-5 cm during the longest detection time of 10 min.According to the detection of nuclide activity of 238U and 235U in the samples and the subsequent calculation of specific activity,the nuclide percentage composition was calculated and the existence of DU was confirmed if this value of 235U was less than 0.718％.Results The activity of 238U was detected using portable γ spectrometer under all test conditions,while the activity of 235U was detectable only under certain test conditions (MA ≥ 1 g,DN ≤ 1 cm).Under the condition that the 238U and 235U was both detected,the nuclide percentage of 235U was all less than 0.718％,which suggested that the DU was confirmed.Conclusions The energy spectrum of low activity of DU and the type of nuclide could rapidly be identified and evaluated by using portable γ spectrometer.This is same as the conclusions obtained with high purity Ge γ spectrometer,α spectrometer and ICP-MS.
ABSTRACT
Objective To construct the eukaryotic expression vector for mouse microRNA miR-21 and identification its expression activ-ity in 293 cells. Methods The genomic sequence containing pre-miR-21 was amplified from mouse genomic DNA by PCR and cloned into the pRC/CMV plasmid. The constructed recombinant plasmid pRC/CMV-mmu-miR-21 was transfected to 293 cells by lipofectamine 2000, and the stably transfected cells were screened with G418,from which total RNA was extracted for detecting the expression of mature miR-21 by northern blot. In the meantime,a luciferase report plasmid examing the activity of miR-21 named pmiR-21-Luc reporter was also construc-ted,and luciferase activity analysis indicated the product of pRC/CMV-mmu-miR-21 indeed had biological activity. Results Both restriction enzyme digestion analysis and sequencing proved the recombinant plasmids were constructed correctly. The miR-21 was highly expressed in the screened clones of 293 cells and it had good biological activity. Conclusion The eukaryotic expression plasmid of mouse miR-21 was successfully constructed,which laid the foundation of further investigation of the role of miR-21 during skin wound healing.
ABSTRACT
Objective To explore the effect of long-term depleted uranium (DU)ingestion on testosterone production in rats, and its involvement mechanism. Methods Male and female rats (F0 and F1 respectively) for 160 days, respectively. The contents of testosterone (T), luteinizing hormone (LH), and follicle stimulating hormone (FSH) in serum were detected in 20 months of F0 generations, and 15 months of F1 generations. RT-PCR was used to analyze the levels of StAR mRNA and P450scc mRNA. Results Compared with the normal control group, the testosterone contents in exposed F0 and F1 generations increased, the lowest was 51.73 U/L, but those of LH and FSH decreased. The expression of StAR mRNA in the low-doze group of F1 generation (StAR/β-actin = 1.35) was up-regulated, down-regulated for other groups.compared with the normal control group (P450scc/β-actin = 0. 313), the expression of P450scc mRNA in the low- and high-dose groups of F0 generation were decreased (P450scc/β-actin = 0.21), and those in the low- and high-dose groups of F1generation were increased (P450scc/β-actin = 0.623) (P ≤ 0.01). Conclusion Long-term DU exposure inhibit the male reproduction by intervening the sexual hormone production through down-regulated the expression of StAR mRNA and P450scc roRNA.
ABSTRACT
Objective To find out the best method for elimination of uranium contamination in rat tissues as low as possible by removal of shrapnel fragments. Methods Experimental rats were divided into six groups: route group, decontamination before surgery group, decontamination in incision group, changing surgical appliances group, removing tissues around group, and comprehensive method group. Uranium concentrations in tissues and fluids in all groups were measured at 7, 14, and 21 d after operation. The efficiency of decontamination by different methods was compared. Results The highest uranium concentration in tissues was found in the route group, but the lowest in the comprehensive method group, and the second lowest in removing tissues around group. Conclusion The comprehensive method is the best one in all of the surgical removal methods. The soft tissues around DU shrapnels should be removed if they are not critical organs.