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The culture of Sertoli cells has become an indispensable resource in studying spermatogenesis. A new Sertoli cell line (POSC) that consisted predominantly of fibroblast-like cells was derived from the testis of the olive flounder Paralichthys olivaceus and sub-cultured for 48 passages. Analysis of the mtDNA COI gene partial sequence confirmed that the cell line was from P. olivaceus. Cells were optimally maintained at 25°C in DMEM/F12 medium supplemented with fetal bovine serum, basic fibroblast growth factor, and epidermal growth factor. The growth curve of POSC showed a typical “S” shape. Chromosome analysis revealed that the cell line possessed the normal P. olivaceus diploid karyotype of 2n=48t. POSC expressed dmrt1 but not vasa, which was detected using RT-PCR and sequencing. Immunocytochemistry revealed that the cells exhibited the testicular Sertoli cell marker FasL. Therefore, POSC appeared to consist of testicular Sertoli cells. Bright fluorescent signals were observed after the cells were transfected with pEGFP-N3 plasmid, with the transfection efficiency reaching 10%. This research not only offers an ideal model for further gene expression and regulation studies on P. olivaceus, but also serves as valuable material in studying fish spermatogenesis, Sertoli cell-germ cell interactions, and the mechanism of growth and development of testis.  相似文献   
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A traditional interpolation algorithm with the linear interpolation method (LIM) using a fixed number of reference stations is widely used in network RTK to obtain the ionospheric delays for the users. In low-latitude regions, where the ionosphere is relatively active, however, large interpolation errors exist, especially for satellites at low elevation angles. Considering the characteristics of “coinciding ionospheric pierce points (CIPPs)” with a similar nature of ionospheric delays, an improved interpolation algorithm is proposed. In this algorithm, all stations with CIPPs are used to establish the interpolation model; thus, more precise interpolation model is achieved. To validate the performance of the proposed algorithm, data from some reference stations in Guangdong Province of China were used, and the results are compared with those with the traditional interpolation algorithm. Numerical analysis shows that the interpolation accuracy of the proposed algorithm increases by 10–30% compared with the traditional one. Since the number of reference stations is flexible, the proposed algorithm can also balance the model accuracy with the computation burdens. In addition, the proposed algorithm is less affected by the selection of master reference station. In terms of network RTK on-the-fly positioning, the time-to-first-fix is reduced when replacing the traditional interpolation algorithm with the proposed one.  相似文献   
66.
Xiong  Pingping  Zou  Xia  Yang  Yingjie 《Natural Hazards》2021,107(3):2517-2531
Natural Hazards - The linear relationship of the original grey prediction model is too single, and the original grey prediction model does not consider the time delay of the effect of the current...  相似文献   
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岩土参数的正态分布是岩土工程可靠分析的基本假定之一。目前,岩土工程参数的正态性检验以KS (Kolmogorov-Smirnov)检验为主,然而诸多研究表明,对于小样本数据,KS检验的正态性检验结果并不可靠。本文以废黄河泛滥沉积相粉土中的孔压静力触探(CPTU)锥尖阻力qt数据为研究对象,首先采用ANOVA (方差分析)检验,从CPTU测试资料中进行总体的样本筛选,然后应用SW (Shapiro-Wilk)检验、KS检验、LF (Lilliefors)检验和AD (Anderson-Darling)检验等4种正态性检验方法,在不同样本容量条件下,对测试数据进行正态性检验评价。当测试数据的样本容量充足时,分析结果表明:SW检验结果最为严格,KS检验结果最不保守,而LF检验和AD检验的严格性介于两者之间;对于常规岩土工程设计,采用KS检验结果即可满足稳定性分析要求,对于复杂岩土工程设计,采用SW检验对设计参数进行正态性检验,可降低设计的不确定性。  相似文献   
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为探究冻融循环对节理岩石抗剪力学特性的影响,针对冻融循环前后不同连通率节理岩石试样进行剪切特性试验,探究了节理试样的剪切破坏机制,对比分析了冻融前后节理试样抗剪强度的衰减趋势,分析了黏聚力及内摩擦角随岩石试样剪切破坏面分形维数的变化规律。结果表明:随冻融循环次数的增加,节理试样剪切应力-位移曲线发生显著变化,峰值剪应力出现明显下降,黏聚力及内摩擦角对比冻融前试样出现明显劣化,并且随节理试样连通率的增加,劣化程度加剧;在节理连通率相同时,随冻融循环次数的增加,剪切破坏面的分形维数呈现近指数函数递增的趋势,随分形维数的增加,节理试样的黏聚力损伤因子、内摩擦损伤因子也呈现指数函数增加的趋势;在冻融循环次数相同时,内摩擦角损伤因子随节理连通率的增大呈先减小后增大的趋势,而黏聚力损伤因子在冻融循环次数为30次前后分别呈递增和先减后增的趋势。  相似文献   
69.
Wang  Yihan  Ma  Gang  Mei  Jiangzhou  Zou  Yuxiong  Zhang  Daren  Zhou  Wei  Cao  Xuexing 《Acta Geotechnica》2021,16(11):3617-3630
Acta Geotechnica - Grain morphology has significant impacts on the mechanical behaviors of granular materials. However, its influences on grain breakage are still poorly understood due to the...  相似文献   
70.
On the basis of field geological studies of the granotoids in the region, mineralogical, petrological, geochemical(including stable isotope geochemical) and isotopic geochronological investigations were carried out on selected representative granitic bodies of various types. The authors have concluded that, apart from the bodies of the orogenic granitoid series, there also exist intrusions of the anorogenic granitoid series in the region. The intrusives of the two series were formed not only in different ages and tectonic environments, but also were derived from different sources of materials. Moreover, they are associated with different mineralizations, belonging to different minerologenetic series(Cheng et al., 1983). They show distinctly a series of discriminative criteria. The problems under discussion in the present paper are of important theoretical and practical significance in the studies of granites of the orogenic belt, particularly the studies of the genesis and related metallogeny of the granites of the region.  相似文献   
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