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羊栖菜(Sargassum fusiforme)多糖在多种肿瘤细胞系中表现出良好的抗癌活性,具有针对肿瘤细胞的选择活性和较小的毒副作用,可以作为现有肿瘤化疗药物的替代品进行开发。羊栖菜多糖主要通过诱导细胞凋亡作用于肿瘤细胞,其通过细胞周期停滞,增强机体免疫功能,改变细胞膜钙通道与流动性,破坏线粒体膜和产生一氧化氮来杀死癌细胞并防止转移。本文就国内外发表的羊栖菜多糖抗肿瘤功能及作用机制进行系统的归纳和总结,旨在为羊栖菜多糖抗肿瘤药物的深入研究、开发提供理论依据。  相似文献   
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Nitrogen balance method and nitrogen-free diet were used in this study to determine nitrogen maintenance requirement (NM) and nitrogen maintenance requirement per unit metabolism body weight (NM′) of black porgy Acanthopagrus schlegeli. Fish with body weight (BW) of 50, 80, 120, 160 and 200 g were fed by the diets containing three graded levels of crude protein (380, 420 and 460 g/kg). The results from nitrogen balance experiment showed that the amount of nitrogen deposition varied from 0.15 to 0.31 mg/g BW per day, accounting for 12.2% to 21.1% of nitrogen intake. The amount of fecal nitrogen excretion varied from 0.21 to 0.32 mg/g BW per day, accounting for 16.3% to 21.6% of nitrogen intake. The endogenous nitrogen excretion, a main part of nitrogen consumption varied from 0.79 to 0.97 mg/g BW per day, accounting for 63.3 % to 68.0% of nitrogen intake. Positive correlation was found between NM and body weight, while a negative correlation was found between NM of unit body weight and the growth duration. No significant differences (p>0.05) were found in NM′ among different growth stages. The average of NM′ was 0.485 7mg/g per day. The results from nitrogen-free diet experiment showed that a negative correlation between NM and feed intake of nitrogen-free diet. NM increased with the decrease of feed intake of fish. The average of NM was 0.482 9 mg/g BW per day that was close to 0.483 8 mg/g BW obtained from fish with 120 g BW in nitrogen balance experiment. The nitrogen balance method is recommended to be a better method for determining NM in consideration of fish stress and result stability. This study also provides a calculated result of the protein content in diets, which is necessary for maintaining fish body protein at different growth stages. The calculation was based on the amount of nitrogen required for maintaining body protein per kg BW. Supported by Scientific Research Project Grant (No.2004C100059) from the city government of Ningbo, China.  相似文献   
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汪财生  李共国 《湖泊科学》2006,18(6):643-648
本文调查了疏浚后杭州西湖(小型、浅水、富营养化湖泊)四个采样站(Ⅰ-Ⅳ)桡足类的密度、生物量和多样性指数,并对桡足类生物量与水质理化因子之间进行了相关分析.共发现桡足类9种,其中哲水蚤3种,剑水蚤6种.疏浚后,桡足类群落密度随着引水水流路程的加大而逐渐增大,多样性指数逐渐下降.桡足类群落丰度夏秋季明显大于冬春季.汤匙华哲水蚤(Sinocalanus dorrii)成体在营养水平较低的Ⅰ站(TLI=55.3)具有较大的密度和生物量,其分市沿着引流方向逐渐下降,而哲水蚤的桡足幼体则沿引流方向逐渐增加;粗壮温剑水蚤(Thermocyclops dybowskii)成体在营养水平较高的Ⅱ-Ⅳ站(TLI=62.7-63.5)具有较大的密度和生物量;疏浚使底柄种类猛水蚤(Harpacticoida)消失了.疏浚对哲水蚤密度分布分异的影响较大,对剑水蚤密度分布分异的影响较小.桡足类群落Ⅱ-Ⅲ站桡足类生物量随水体叶绿素a、高锰酸盐指数和总磷含量的升高而显著增加,随水体透明度的增大而显著下降.  相似文献   
4.
Nitrogen balance method and nitrogen-free diet were used in this study to determine nitrogen maintenance requirement (NM) and nitrogen maintenance requirement per unit metabolism body weight (NM’) of black porgy Acanthopagrus schlegeli. Fish with body weight (BW) of 50, 80, 120, 160 and 200 g were fed by the diets containing three graded levels of crude protein (380, 420 and 460 g/kg). The results from nitrogen balance experiment showed that the amount of nitrogen deposition varied from 0.15 to 0.31 mg/g BW...  相似文献   
5.
日本沼虾染色体倍性检测技术的研究   总被引:2,自引:0,他引:2  
用流式细胞仪分别对日本沼虾(Macrobrachiumnipponense)正常二倍体的体细胞和四倍阶段体胚胎的DNA相对含量和细胞频率进行了测定,以研究日本沼虾染色体倍性检测技术。以日本沼虾正常二倍体的体细胞液进样所得直方图为标准,用对细胞松弛素B人工诱导的日本沼虾四倍体胚胎进行DNA相对含量和细胞频率的测定,测试结果以直方图表示,并用染色体涂片镜检结果进行倍性核对。结果表明,日本沼虾二倍体和四倍体的DNA相对含量有显著差异,四倍体日本沼虾的DNA相对含量是二倍体的2倍。用流式细胞仪法检测日本沼虾倍性,方法简单、测试速度快、结果可靠。  相似文献   
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