| 1 | Exogenous rare earth element-yttrium deteriorated soil microbial community structure显示文摘In this study, we selected yttrium as the representative of REEs to investigate the impacts of exogenous yttrium on soil physicochemical properties and microbiota. The results showed that exogenous yttrium has no significant effect on soil physical properties but a significantly negative impact on soil chemical properties. The results of high-throughput sequencing demonstrate that exogenous yttrium significantly decreases the number of OTUs, ACE, Chao 1, and Shannon indices while increases the Simpson index(P < 0.05), indicating the low soil microbial diversity. The relative abundances of soil microbes are significantly changed at phylum and genus level. Principal component analysis(PCA) showed the significant difference of microbial community between yttrium treatments(YCl_3-250 and YCl_3-500) and non-yttrium treatment(CK) and the similarity of that between YCl_3-250 and YCI_3-500. Proteobacteria and Bacteroidetes are found to be the most tolerant phyla to exogenous yttrium while Verrucomicrobia the most sensitive phylum. Redundancy analysis(RDA) results suggest that exogenous yttrium affects soil microbiota only through changing the soil chemical properties but not soil physical properties, and C/N ratio is the key environmental factor. | Caigui Luo Yangwu Deng Jian Liang Sipin Zhu Zhenya Wei Xiaobin Guo Xianping Luo | 2018 | Journal of Rare Earths2018，36，4： | 5 |
| 2 | Effect of constant compressive stress induced by imitating tuina stimulation with various durations on the cell cycle,cellular secretion,apoptosis,and expression of myogenic differentiation and myogenic factor 5 of rat skeletal muscle cells in vitro显示文摘OBJECTIVE:To investigate the effect of constant compressive stress induced by imitating Tuina stimulation with various durations on the cell cycle,cellular secretion,apoptosis,and expression of myogenic regulatory factors(MRFs),myogenic factor 5(Myf5)and myogenic differentiation(MyoD)of rat skeletal muscle cells(RSkMCs)in vitro.METHODS:Third passage RSkMCs were subjected to constant compressive stresses with various durations at 2000μstrain for 15,30,60,90,and 120 min via a four-point bending system.The control group(CG)was cultured in the absence of mechanical loading.Alterations of the cell cycle and apoptosis rate were detected by flow cytometry(FCM).The concentrations of interleukin 6(IL-6)/prostaglandin E2(PGE2)and nitric oxide(NO)in supernatants were determined by enzyme-linked immunosorbent assays and the nitrate reductase method,respectively.Expression of Myf5 and MyoD was detected by immunohistochemistry.RESULTS:Compared with the CG,a significant alteration was observed in the synthesis phase fraction(SPF)(P<0.01).The SPF and proliferation index(PI)were reduced from 15 to 90 min,but reached levels similar to those at 120 min.Apoptosis was increased significantly at 30 min(P<0.05)and especially at 90 and 120 min(P<0.01).Expression of MyoD and Myf5 was increased significantly at 15,30,and 90 min(P<0.01).Compared with 15 and 30 min,MyoD and Myf5 expression at 60 and 120 min was decreased significantly(P<0.01).Compared with 60 min,M yoD expression at 90 min was increased significantly(P<0.05),whereas MyoD and Myf5 expression at 120 min was significantly lower(P<0.05).The IL-6 concentration was increased at 60 min compared with the CG and 15 min(P<0.05),whereas the concentrations of PGE2 and NO were the highest at 15 and 30 min,respectively,compared with the CG and other time points(P<0.05).CONCLUSION:The cell cycle,secretion,apoptosis,and Myf5 and MyoD expression of RSkMCs were regulated by compressive stress in a time-dependent manner.SPF and PI were inhibited at short durations(<90 min),but NO and PGE2 secretion was the highest at shorter durations(<30 min).With the prolongation of stimulation time,SPF,PI,and apoptosis were increased,but Myf5 and MyoD expression was decreased gradually at 15-30 min. | Lu Qunwen Su Chengguo Liu Huahui Luo Caigui Yan Bohua | 2020 | Journal of Traditional Chinese Medicine2020，40，4： | 1 |
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