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121.
122.
Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell
culture from amphioxus tissues in vitro would help understanding some basic issues. To determine the optimal culture conditions for proliferation of amphioxus cells,
primary cultures were initiated from buccal cirri, tail, gill, gut and metapleural fold of amphioxus Branchiostoma belcheri tsingtauense. The media tested were L-15, F-12, M 199, MEM, DMEM, PRMI 1640 and LDF, each was supplemented with 20% fetal bovine serum.
The optimal conditions include tail tissue cultured in L-15 or F-12 with supplement of 20% FBS and 1.5% NaCl at about 25°C.
Supported by Doctoral Initial Fund of Ludong University (No.43304) 相似文献
123.
124.
Special primers were designed based on the sequence information of superoxide dismutase genes reported in the Iiterature and were used for RT-PCR and rapid amplification of cDNA ends(RACE) to clone Tegillarca granosaMn-superoxide dismutase gene successfully.The length cDNA of Tegillarca granosaMn-superoxide dismutase gene was of 635bp by including a 3'untranslated region(UTR)of 230bp and an open reading frame(ORF) of 4.5bp encoding a polypeptide of 135 amino acids. TheTegillarca granosaMn-superoxide dismutase gene shares 66%~73% homology with Mizuhopecteb yessoensis's,Danio rerio's,Xenopus Laevis's,Human's,Callinectes sapidus'sSOD CDS, while the corresponding amino acids shares 68%-78% homology and 80%~89% comparability. These indicate the SOD gene is high evolutional conservation in animals. 相似文献
125.
Optimizing support vector machine learning for semi-arid vegetation mapping by using clustering analysis 总被引:1,自引:0,他引:1
In remote sensing communities, support vector machine (SVM) learning has recently received increasing attention. SVM learning usually requires large memory and enormous amounts of computation time on large training sets. According to SVM algorithms, the SVM classification decision function is fully determined by support vectors, which compose a subset of the training sets. In this regard, a solution to optimize SVM learning is to efficiently reduce training sets. In this paper, a data reduction method based on agglomerative hierarchical clustering is proposed to obtain smaller training sets for SVM learning. Using a multiple angle remote sensing dataset of a semi-arid region, the effectiveness of the proposed method is evaluated by classification experiments with a series of reduced training sets. The experiments show that there is no loss of SVM accuracy when the original training set is reduced to 34% using the proposed approach. Maximum likelihood classification (MLC) also is applied on the reduced training sets. The results show that MLC can also maintain the classification accuracy. This implies that the most informative data instances can be retained by this approach. 相似文献
126.
东营凹陷2001年之前探明的低渗透油藏主要分布在洼陷带、中央背斜带及北部陡坡带,以沙三段深水浊积扇及沙四段滨浅湖相砂岩滩坝、扇三角洲前缘等沉积体系为主。油藏类型主要是岩性油藏,其次为构造—岩性复合型油藏。低渗透油藏以中深层、常压-超高压、低产、中产为特征,多为特小型、小型油藏,储量丰度为低丰度~特低丰度。低渗透油藏的探井试油过程中,经历了从酸化逐步到压裂的技术发展过程。统计探井的试油效果表明,沙四段碳酸盐含量较高的砂岩低渗透油藏,酸化效果较好;黏土含量较高的沙三段低渗透油藏,压裂效果较好。 相似文献
127.
128.
We extracted marine low-temperature lysozyme (MLTL), a novel lysozyme, from a marine microorganism through fermentation. Our
previous study suggested that a low molecular weight (16 kDa) may exert anti-tumor activity through antiangiogenesis. In this
study, we extracted a high weight (39 kDa) and investigated its antiangiogenic activity in vivo and in vitro. Using zebrafish embryos as an in vivo study model, we found that treatment with MLTL significantly inhibited the growth of subintestinal vessels (SIVs) in a dose-dependent
manner and that 400 μg/ml MLTL was sufficient to block the growth of SIVs. An in vitro study conducted using human umbilical vein endothelial cells (HUVECs) revealed that MLTL suppressed the proliferation, migration
and tube formation of HUVECs in a dose-dependent manner. Interestingly, assays by flow cytometry and DNA electrophoresis indicated
that MLTL was able to induce apoptosis of HUVECs. Moreover, further study demonstrated that the disruption of intracellular
Ca2+ homeostasis may play an important role in MLTL induced apoptosis of HUVECs. Taken together, the results of this study demonstrate
for the first time that MLTL inhibits angiogenesis through its pleiotropic effects on vascular endothelial cells and induces
apoptosis through regulation of cellular Ca2+ levels. The results of this study also revealed a possible mechanism underlying the antiangiogenic effect of MLTL and suggested
that MLTL may be a promising new antiangiogenic agent for use in cancer therapy. 相似文献
129.
耿达短水准异常与汶川8.0级地震 总被引:2,自引:1,他引:1
结合龙门山断裂带其他跨断层资料,对耿达短水准在汶川8.0级地震前后的观测资料进行了重新分析,发现耿达短水准在汶川地震前后的异常为当地居民修建生活小区所致,不应视为地震前兆异常。 相似文献
130.
The trends of distribution, translocation and seasonal change of heavy metal Pb were studied based on the surface and bottom water sampling in Jiaozhou Bay in 1979, and compared with those in 1990's. The results showed that the source of Pb in the bay was from wastewater and sewage in the east of Jiaozhou Bay from ocean vessels. Pb concentration was higher in spring and lower in summer and autumn, and remained stable through sedimentation in the bottom layer. The overall water quality was good in 1970's. Compared with the environmental monitoring data of 1995-1999, Pb pollution had become serious. Therefore, more efforts should be made to protect the bay from Pb pollution. 相似文献