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1.
ABSTRACT: An application of the acoustic Doppler current profiler (ADCP, 153.6 kHz) in combination with a scientific echo sounder (EK60, 38 and 200 kHz) was investigated to estimate the density of krill Euphausia pacifica . The acoustic backscattering strength from sound scattering layers was compared with biomass estimates from midwater trawls. Euphausia pacifica was targeted among mixed species populations in the sound scattering layer in the offshore Funka Bay area of Hokkaido, Japan. The frequency characteristics of acoustic backscattering by krill were calculated using a distorted wave Born approximation scattering model at three frequencies. Krill aggregations identified from the EK60 data were extracted as the mean volume backscattering strength difference between two frequencies. They were then used to identify similar aggregations in the ADCP data by matching observation times and depths for the two methods, which were applied simultaneously. Results from the comparison of the mean volume backscattering strength and the density calculated from the ADCP and EK60 showed that ADCP can be used to measure density and spatial–temporal distribution of krill aggregations. Current speed and direction at the study site were found to be 16.1 cm/s and 187.0°, respectively, and krill speed and direction (including the current component) were found to be 19.8 cm/s and 172.2°, respectively. Based on the ADCP data, the net speed and direction of the krill aggregations were found to be 5.9 cm/s and 128.0°, respectively. 相似文献
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按 0 .2 m g/ kg单剂量对健康仔猪肌注亚硒酸钠溶液后 ,研究了其在血液中的药物代谢动力学。结果表明 :血液动力学特征符合一级吸收二室开放模型 ,其理论方程为 :C=0 .1773e- 0 .0 548t+0 .0 72 7e- 0 .0 0 2 6 t- 0 .2 5 0 0 e- 1 3.882 3t。主要动力学参数为 :吸收半衰期 (t1 /2 Ka)为 0 .0 4 99h;达峰时间 (tmax)为 0 .4 2 37h;消除半衰期 (t1 /2β)为 2 71.9311h;曲线下面积 (AU C)为 31.72 6 0 m g/ L·h;表观分布容积 (Vd)为 2 .4 72 1L/ kg。根据单剂量药动学参数 ,计算多剂量给药参数 ,为临床治疗制定给药方案。先导剂量 (D* )为 0 .5 0 89m g/ kg,维持剂量 (D0 )为 0 .2 mg/ kg,给药间隔 (τ)为 192 h,平均稳态血药浓度 (c)为 0 .16 5 2 mg/ L。 相似文献
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JIANG An-li KANG Lu-dong ZHAO Chun-hua BI Wen-xiang HU Xiao-yan KONG Feng XU Song-de 《园艺学报》2003,19(1):55-58
AIM: In order to evaluate the applicable value of LDL as a targeted vehicle for chemotherapeutic agents, we investigated and compared the inhibitory effects of LDL-ACM complex and free ACM on nude mice's subcutaneous implanted tumors derived from gastric cancer cell lines, SGC-7901 and NKM-45. METHODS: LDL-ACM complex was prepared and the tumor model of nude mice was established by subcutaneous implantation of SGC-7901 and NKM-45. Then, the groups of nude mice developed subcutaneous implanted tumors were received either LDL-ACM complex or free ACM. Subsequently, the tumor size, weight and leukemia cell counts were measured and the rates of tumor-inhibition and the survival were compared among the groups. RESULTS: The inhibitory effects of LDL-ACM complex on the tumors, especially on SGC-7901 implanted tumors were much more obvious than that of free ACM. It was also indicated that the action of LDL-ACM complex was mediated by LDL receptor. CONCLUSION: These results showed that LDL-ACM complex had significant inhibitory effects on the implanted tumors and the effect might be mediated by LDL receptor. 相似文献
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试验选择处于热应激条件下的192只35周龄新罗曼褐壳蛋鸡,随机分为6组,分别饲喂添加0.10,20,30,40,50 g/t含铬量为7.410mg/kg的葡萄糖耐量因子(GTF)的玉米—豆粕型基础日粮52d。试验结束时随机抽取试验鸡36只(每组6只),取肾上腺称重并制作切片,研究有机铬对热应激蛋鸡肾上腺组织结构的影响。结果试验组肾上腺重量较对照组略有增加;热应激时蛋鸡肾上腺的肾间组织比例增大,肾间组织和嗜铬组织的细胞均有结构受损的现象;补铬使肾间组织比例减小,嗜铬细胞增多,细胞结构完好。 相似文献
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相似离度的沙尘暴预报业务系统 总被引:1,自引:0,他引:1
选择1988年以来ECMWF资料齐全的沙尘暴个例,将其按区域分为全区、西部、中部、中西部以及中东部5类,再按强弱分别分为强和一般2类,建立不同的样本库。根据多年预报经验建立消空指标,对实时资料进行消空,在消空的基础上,用相似离度分析方法对ECMWF的3个场(500hPa高度场、850hPa温度场和海平面气压场)的历史资料库和实时资料进行比较,制作不同时次的沙尘暴预报。并利用VB和Fortran语言编程,建立沙尘暴预报业务系统,用人机交互的方式完成预报的制作,实现预报结果在Micaps系统下的自动显示。 相似文献
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本研究分离培养尼罗罗非鱼(Oreochromis niloticus)精巢支持细胞(Sertoli cells, SCs),建立并优化尼罗罗非鱼精巢支持细胞分离培养体系。无菌条件下,取发育至第Ⅲ期的尼罗罗非鱼精巢,PBS清洗后,剪碎精巢组织,0.25%胰蛋白酶消化,用含10%犊牛血清(Newborn bovine serum, NBS)的L-15培养液终止消化,过滤、离心,获得细胞。差速贴壁法获得SCs后,在26℃、无CO2饱和湿度恒温培养箱中培养。分别采用含10% NBS的L-15、M199、F12培养液,含5%、10%、15% NBS的L-15培养液,含1%罗非鱼血清的L-15+10% NBS培养液培养尼罗罗非鱼SCs。各组每2 d取细胞计数,绘制SCs生长曲线;甲基绿染色,倒置显微镜下观察SCs的形态。尼罗罗非鱼SCs培养1~2 d,细胞贴壁;培养3~5 d,细胞完全贴壁并迅速增殖。单个SCs呈不规则多边形,其核位于胞质中央,呈卵圆形,胞质中可见吞噬颗粒和空泡,空泡聚集于支持细胞胞质的两极或散布于核的四周。SCs在L-15培养液中贴壁生长,在F12、M199培养基中较难贴壁。与F12、M199培养液相比,L-15培养液更有助于尼罗罗非鱼SCs生长增殖(P<0.01)。与添加5%和15% NBS相比,在L-15培养基中添加10% NBS更有助于尼罗罗非鱼SCs生长增殖(P<0.05)。与未添加尼罗罗非鱼血清相比,在10% NBS+L-15培养中添加1%尼罗罗非鱼血清,能显著促进SCs生长增殖(P<0.05)。研究表明,采用胰酶消化差速贴壁法获得尼罗罗非鱼精巢支持细胞,10% NBS+1%罗非鱼血清+L-15培养液培养,能显著促进尼罗罗非鱼精巢支持细胞生长增殖。 相似文献