环境胁迫对鱼类免疫系统影响的研究概况

<正> 环境胁迫(environmental stress)是指环境对鱼类所处的生存状态产生的压力,可以分为急性环境胁迫和慢性环境胁迫。捉捞(handling)和干扰(disturbance)等引起急性环境胁迫,而水质逐渐恶化和高密度放养等造成慢性胁迫。随着世界人口的增长和消费水平的提高,世界渔业也得到了长足的发展。但与此同时,由于人类活动范围的扩大、程度的加深,

新型笼状同多钒酸盐[Ni(1,10′-phen)_3]_2·[V_2~ⅣV_8~ⅤO_(26)]的水热合成和晶体结构

尽管多金属氧酸盐 (POMs)的研究已有180多年的历史,但大量的POMs结构在最近几十年才被陆续解析出来[1～4].其中 ,同多钒酸盐由于钒配位几何形状的多样性,结构最为丰富 ,例如:[V4 O12 ]4-[5],[V5O14 ]3-[6],[V10 O2 8]6-[7] ,[V15O4 2 ]9-[8],[V13 O3 4 ]3-[9].值得注意的是,在这些化合物中,钒的化合价均处于最高氧化态+5价.由于+4价钒不易在溶液中(尤其是水中)稳定存在,因此在以往的常压溶液合成中具有混合价态的同多钒酸盐报道很少.与饱和价态的同多钒酸盐相比,混价多钒酸盐具有更为新奇的电荷分布和拓扑学几何构型,并且在 POMs的理论研究和抗病毒药物、电存储材料以及磁性材料等应用领域有特殊的研究和开发价值[1,10,11].因此,制备具有混价的新型同多钒酸盐一直倍受关注.近年来,水热合成技术的引入使同多钒酸盐合成化学迅速发展.水热体系提供了一个特殊的反应环境 [12 ],使制备各种具有混合价态的同多钒酸盐成为可能.Müller等[13]对这一领域开...

ELECTROCHEMICAL STUDY OF ISOPOLYOXOMETALLATES AND HETEROPOLYOXOMETALLATES FILM MODIFIED MICROELECTRODES .1. PRETREATMENT AND MODIFICATION OF THE MO80-26(4-) MODIFIED CARBON-FIBER MICROELECTRODE

In this paper the preparation of isopoly- and heteropolyoxometallates (IPA and HPA) thin film modified carbon fiber (CF) microelectrodes and the factor that influences the modification of IPA and HPA films are described. IPA and HPA film modified CF microelectrodes can all be prepared by cyclic potential scan and simple dip coating. The modified electrodes prepared are very stable and reversible in acidic solution with monolayer characteristics. The electrochemical pretreatment of CF microelectrodes plays an important role in the modification of IPA and HPA film. The absorption of IPA and HPA film on electrode surfaces has been discussed on the basis of surface conditions of the CF microelectrode and the structure of IPA and HPA.

Genetic improvement on Chinese shrimp (Fenneropenaeus chinensis): growth and viability performance in F1 hybrids of different populations

Fenneropenaeus chinensis distributed in the Yellow Sea and Bohai Sea of China and the west coast of the Korean Peninsula. Different geographical populations represent potentially different genetic resources. To learn further the characteristics of different geographical population, crosses among two wild and three farmed populations were produced. The two wild populations were from the Yellow Sea and Bohai Sea (WYP), and the west coast of the Korean Peninsula and coast (WKN). The three farmed populations included the offspring of first generation of wild shrimp from coast in Korea (FKN), the Huang Hai (the Yellow Sea in Chinese) No.1 (HH1), and JK98. The phenotypes growth and survival rates of these populations were compared to confirm the feasibility for crossbreeding. The body length (BL), carapace length (CL), carapace width (CW), height of the second and third abdominal segment (HST), width of the second and third abdominal segment (WST), length of the first abdominal segment (LF), length of the last abdominal segment (LL), live body weight (BW), and survival rate were measured. Different combinations were statistically performed with ANOVA and Duncan's Multiple Range Test. The results show that the survival rate of JK98(a (TM) Euro)xWKN(a (TM),) was the highest, followed by WYP(a (TM) Euro)xWKN(a (TM),), FKN(a (TM) Euro)xWYP(a (TM),), FKN(a (TM) Euro)xHH1(a (TM),) and WYP(a (TM) Euro)xFKN(a (TM),); the body weight of FKN(a (TM) Euro)sxHH1(a (TM),) was the highest, followed by FKN(a (TM) Euro)xWYP(a (TM),), WYP(a (TM) Euro)xWKN(a (TM),), WYP(a (TM) Euro)xFKN(a (TM),) and JK98(a (TM) Euro)xWKN(a (TM),); the total length had the same ranking as the body weight. All growth traits in hybrids JK98(a (TM) Euro)xWKN(a (TM),) were the lowest among all combinations. F1 hybrids had significant difference (P < 0.05) in BL, CL, HST, LL, and BW; and insignificant difference (P > 0.05) in other growth traits and survival rate. The results of Duncan's Multiple Range Test are that BL and CL of JK98(a (TM) Euro)xWKN(a (TM),) were significantly different from the other combinations; HST different from the combination of FKN(a (TM) Euro)xWYP(a (TM),), FKN(a (TM) Euro)xHH1(a (TM),) and WYP(a (TM) Euro)xWKN(a (TM),); and BW different from FKN(a (TM) Euro)xWYP(a (TM),) and FKN(a (TM) Euro)xHH1(a (TM),). As a whole, the results indicate that the FKN(a (TM) Euro)xHH1(a (TM),) was the best combination in all growth traits. Therefore, hybridization can introduce the variation to base populations. The systematic selection program based on additive genetic performance may be more effective than crossbreeding.