Generation of reactive oxygen species in different fractions of the coelomocytes of holothurian Eupentacta fraudatrix in response to the thermostable toxin of Yersinia pseudotuberculosis in vitro     

Dolmatova L. S.  Eliseykina M. G.  Timchenko N. F.  Kovaleva A. L.  Shitkova O. A. 《中国海洋湖沼学报》2003,21(4):293-304

Pure fraction (92%–95%) of phagocytes (FP) and a mixture of amoebocytes (62%) and morula cells (38%)-FPMC- of the holothurianEupentacta fraudatrix' (Holothuroidea, Dendrochirota) were obtained by using ficoll-verographine step gradient. Basal production of reactive oxygen species (ROS) in FP quantified by using reduction of nitroblue tetrazolium (NBT) was more than twice that in FPMC. Thermostable toxin ofYersinia pseudotuberculosis (TST) at different concentrations (0.2; 0.5; 2.5 μg/ml, but not 0.1 μg/ml) stimulated NBT reduction in FPMC after 24 h incubation. In FP, TST at concentrations of 0.1 and 0.2 μg/ml inhibited and at concentrations of 0.5 and 2.5 μg/ml stimulated NBT reduction after 24 h incubation. Maximal effect was observed in FP and FPMC at TST concentrations of 0.5 and 0.2 μg/ml, respectively. Addition of catalase (0.7 μg/ml) to the cells treated with TST (2.5 μg/ml) was followed by a decrease in NBT reduction compared to that under toxin treatment alone. TST stimulated superoxide dismutase activity in concentration-dependent manner (maximum at 0.5 μg/ml concentration in FP) after 24 h treatment, and this stimulation was prevented by a commercial catalase. Plant lectin concanavalin A stimulated NBT reduction more than 5-fold in FPMC compared to the control. With addition of TST, lectin stimulated ROS to lesser extent than that with lectin alone. When catalase, TST, and lectin were added into the FPMC simultaneously, ROS increase was similar to that under lectin treatment alone. On the whole, data obtained indicated that ROS generation in holothurian coelomocytes especially occurs in both stimulated and not stimulated phagocytes, and that changes in ROS production by these cells may be one of the mechanisms of antibacterial protection of holothurians. This work was financially supported by the Russian Foundation for Fundamental Research Grant (No. 00-04-48949).  相似文献   

地倾斜台站数字化、模拟观测数据频率特性研究   总被引：2，自引：2，他引：0  

李正媛  陈鹏  林穗平  陈志遥 《大地测量与地球动力学》2003,23(1):74-77

分析了四川、云南的部分地倾斜数字化观测与模拟观测资料的特性，从频率范围，周期10天以上的FFT谱特性，固体潮波振幅，相位特征值等方面，论述了地倾斜数字化资料较模拟记录资料的信息组成变化，并对资料的分析与应用进行了初步探讨。  相似文献   

Strong Tides in 1964 and 1982     

Dianyou Chen  Xuexiang Yang  Qiyuan Qiao 《东北亚地学研究》2003,(1)

1StrongtideandastronomicalconditionsPartial solar eclipse occurred 4 times in 1964, 1982 and 2000 respectively. Time interval is about 3 Saros periods (one Saros period is 18 years and 10.33～11.33 days). Total lunar eclipse occurred 2 times in 1964 and 2000 respectively and 3 times in 1982. However, there was no lunar eclipse in 1966, 1984 and 2002. It seems that they had similar astro-nomical conditions and the best was in 1982. The studies about the effect of tide on the global climate…  相似文献   

小杂鱼脱脂技术的研究     

陈培基  李来好  李刘冬  刁石强 《广东海洋大学学报》2003,23(6):21-26

以小杂鱼或低值鱼为原料 ,采用常温溶剂萃取法进行脱脂 ,研究了不同溶剂、溶剂混合比、流速和萃取时间对鱼类脱脂的影响。结果表明 ,在常温下用等体积的异丙醇和乙酸乙酯混合溶剂 ,以流速 4～ 8mL/min连续萃取 4～ 6h ,脱脂鱼肉的脂肪平均含量w为 0 .19%,脱脂率高达96 .2 6 %。该方法的溶剂损耗量为加热溶剂萃取法的 1/3倍。  相似文献   

Modelling the April 15 spectrum of Supernova 1993 J     

Zhang Qing  Wang Li-fan  Hu Jing-yao  P. A. Mazzali  Wang Zhen-ru 《Chinese Astronomy and Astrophysics》1995,19(4):426-431

We present the modeling of the ultraviolet and optical spectra obtained simultaneously on 1993 April 15 with the HST and at Lick Observatory. A Monte Carlo code is employed in the modeling and a comparison is made between models reported by different groups. With an atmosphere similar to the Sun in chemical composition, the observed spectral lines are well reproduced by a power law density structure of index around 20 except the strong H and HeI λ5876 lines which have peculiar absorption profiles. The photospheric velocity is found to be 9500 km/s and the blackbody temperature of the spectrum is 7990 K. For H and HeI λ5876, we suggest a two-component density structure which has a smoother layer located immediately outside the steeply decreasing inner envelope. The power law indices are most probably 20 and 3, respectively, with the transition point at about 13 000 km/s. In addition, this outer smooth layer serves to flatten the far UV spectrum as observed.  相似文献   

PKI中RA的功能模型及一种实现方式     

张元茂  刘玓 《成都信息工程学院学报》2005,20(1):12-15

网络安全是近年来研究的热点，各种新技术不断涌现，身份认证是安全应用中最重要的一个问题，也是PKI的核心服务之一。PKI作为信息安全的基石经过几年的发展不断走向成熟，在许多领域发挥着重要的作用。针对目前对PKI中的重要部件RA的研究很少的状况，着重对RA的实现模型进行了探讨。  相似文献   

Isolation and pharmacological activities of bromophenols from Rhodomela confervoides     

Han Lijun  Xu Nianjun  Shi Jiangong  Yan Xiaojun  Zheng Chengkui 《中国海洋湖沼学报》2005,23(2):226-229

Four bromophenols were isolated from the extract of marine red alga,Rhodomela confervoides by column chromatography and HPLC methods. By means of spectroscopic methods inclding IR, MS, 1D, and 2D-NMR techniques, their structures were elucidated as (1) 3-bromo-4,5-dihydroxy benzoic acid methyl ester; (2) bis (2,3-dibromo-4,5-dihydroxybenzyl) ether; (3) 3,4-dibromo-5-(methoxymethyl)-1,2-benzenediol and (4) 3-bromo-4,5-dihydroxy-benzaldehyde. Compound 1 was first isolated from the algae in nature, and 1, 4 were found to have selective cytotoxic activities against KB, Bel 7402 and A549 cells, 2 showed powerful antibacterial activities againstStaphylococcus aurens andPseudomonas aeruginosa. Supported by National “863” Program (No. 2004AA625030, 2001AA620503), Quingdao marine sciences project (No. 04-2-NN-26) and Key Knowledge Innovative Project of the Chinese Academy of Sciences (KZCX3-SW-215).  相似文献   

基于负反馈的网络负载调度算法     

付国为  刘心松  冯玮 《成都信息工程学院学报》2006,21(6):779-782

提出一种基于负反馈权值的动态网络负载调度算法。算法主要用在多出口路由器上，其执行效率高，开销小。基于算法的多出口路由器不仅能够很好的保持出口间的负载均衡。还具有良好的出口容错性能。  相似文献   

关于网络企业经济效益的评价理论研究     

岳正华  李黎 《成都信息工程学院学报》2001,16(3):192-198

网络经济是相对于大工业经济而言的，其网络企业经济效益的评价，可以从网络企业成本及收益两个方面讨论，然后以投入产出比等五个方面来建立其评价指标体系。  相似文献   

Fatty Acid Composition Analyses of the DCMU Resistant Mutants of Nannochloropsis oculata (Eustigmatophyceae)     

ZHANG Jimin )  LIU Shuang )  SUN Xue )  YANG Guanpin )  ZHANG Xuecheng )  *  GAO Zhenhui ) ) North China Sea Monitoring Center  SOA  Fushun Road  Qingdao  P..R.China) College of Marine Life Sciences  Ocean University of China  Qingdao  P..R.China 《中国海洋大学学报(英文版)》2003,2(1)

1　Introduction　Nannochloropsissp .areoneofpotentialsourcesofpolyunsaturatedfattyacids ,especiallytheeicosapen taentaenoicacid (EPA ,C2 0∶5 ) ,whichisimportantforbothanimalsandhumans .　Thefattyacidcompositionofthisalgaisaffectedbyvariousenvironmentalfactors ,suchaslightintensity(Sukeniketal.,1989;Sukeniketal.,1990 ) ,imply ingthatafactorinfluencingthephotosyntheticprocessmayaffectcellularfattyacidsynthesisandtheirmetabolism .AselectionprogramofincreasingcellularEPAcontenthasbeencarriedo…  相似文献