DETERMINATION OF TRACE AMOUNT OF 14 RARE-EARTH IMPURITIES IN HIGH-PURITY YTTRIUM-OXIDE WITH ICP-AES

A method of analysis of high purity yttrium oxide with ICP-AES was described with emphasis on the study of Y_2O_3 matrix effects. The results showed that the line intensities of ana]ytes decreased with the increase of Y_2O_3 concentration in solution because of following factors. (1) The presence of matrix resulted in the decrease of the amount of analytes reaching ICP. (2) Matrix Y_2O_3 entering the plasma decreased the excitation temperature of the plasma and depressed the ionization of analytes in the pl...

INVESTIGATIONS ON THE ENERGY-TRANSFER OF EXCITED PARTICLE COLLISION WITH DOUBLE LASER LINES FOR EXCITATION OF LA(I)

Generally speaking, productions of thermally-assisted and stepwise fluorescence are the consequence of energy transfer caused by particle collision. In some circumstances, energy transfer caused by particle collision is considerably intense. We have ever used the fluorescence produced by energy transfer of particle collision to measure the branching ratios in the atomic transitions and acquired good results. To our knowledge, the systematic in

MEASUREMENT OF SPONTANEOUS EMISSION BRANCHING RATIOS IN MO(I) TRANSITIONS BY LASER-INDUCED SENSITIZED FLUORESCENCE

I. TNTRODUCTIONThe emission spectroscopic method is usually used to measure spontaneous emission branching ratios. As emission spectra cannot be detected in atomic beams, the laser-induced fluorescence or ion detection method is often used. When the fluorescence method is used to measure branching ratios, it is usually necessary to detect

牙鲆rag基因的克隆及表达研究

牙鲆在中国北方沿海地区形成了大规模的工厂化养殖，成为我国海水养殖的一大重要产业。然而疾病的频繁发生严重阻碍了这一产业的发展，为了保证牙鲆产业稳定、健康、持续地发展，开展鱼类免疫系统的基础研究，提高鱼类抵抗病原菌侵害的能力，本研究从牙鲆免疫系统的个体发育过程入手，克隆了其rag（recombination activating gene）基因，在此基础上对其组织特异性表达进行了分析。 研究结果表明牙鲆rag1基因由4个外显子和3个内含子组成，第一个外显子位于5’非翻译区，这一外显子存在两种不同的剪切方式。牙鲆rag1基因编码1068个氨基酸。牙鲆rag2基因的编码区序列长为1602 bp，编码533个氨基酸，没有在牙鲆rag2基因编码区内发现内含子的存在。rag基因间序列长为3128 bp，两个基因共用一段3’非编码区。 本试验通过RT-PCR检测发现，牙鲆的rag1和rag2基因在头肾和体肾中均有表达。整装原位杂交结果表明，牙鲆在受精后第8天开始起有rag1和rag2基因的表达，主要在胸鳍前面，腮背部的部位表达，这个区域与后来胸腺出现的位置相一致。冰冻切片结果显示，rag是在靠近咽部的区域有表达。石蜡切片原位杂交结果显示，rag基因在胸腺中的表达显示出不均一性，着色较深的为皮层区，而着色比较浅的为髓部。 将牙鲆rag1基因的一部分（编码559个氨基酸）和rag2全基因序列（编码533个氨基酸）插入到表达质粒pProEXTM HTa上，在大肠杆菌E. coli BL-21中进行体外表达与分析，结合BD TALONTM Metal Affinity Resins亲和柱纯化了RAG2蛋白。

Fucoidan protects against dopaminergic neuron death in vivo and in vitro

Parkinson's disease is a neurodegenerative disorder of uncertain pathogenesis characterized by a loss of dopaminergic neurons in substantia nigra pars compacta, and can be modeled by the neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). Oxidative stress may contribute to MPTP- and Parkinson's disease-related neurodegeneration. Fucoidan is a sulfated polysaccharide extracted from brown seaweeds which possesses a wide variety of biological activities including potent antioxidative effects. Here we investigated the effect of fucoidan treatment on locomoter activities of animals, striatal dopamine and its metabolites and survival of nigral dopaminergic neurons in MPTP-induced animal model of Parkinsonism in C57/BL mice in vivo and on the neuronal damage induced by 1-methyl-4-phenylpyridinium (MPP+) in vitro, and to study the possible mechanisms. When administered prior to MPTP, fucoidan reduced behavioral deficits, increased striatal dopamine and its metabolites levels, reduced cell death, and led to a marked increase in tyrosine hydroxylase expression relative to mice treated with MPTP alone. Furthermore, we found that fucoidan inhibited MPTP-induced lipid peroxidation and reduction of antioxidant enzyme activity. In addition, pre-treatment with fucoidan significantly protected against MPP+-induced damage in MN9D cells. Taken together, these findings suggest that fucoidan has protective effect in MPTP-induced neurotoxicity in this model of Parkinson's disease via its antioxidative activity. (C) 2009 Elsevier B.V. All rights reserved.

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.

A new diterpenoid, taibairubescensin C, from Isodon rubescens

A new kaurenoid, taibairubescensin C (1), was isolated from the ethanol extract of the leaves and tender branches of Isodon rubescens (Hemsl.) Hara. Its structure was designated as 2beta,6alpha-diacetoxy-3beta, 11beta-dihydroxy-ent-kaur-16-en-15-one (1) on the basis of detailed spectroscopic analysis.

ent-kaurene diterpenoids from Isodon rubescens

Two kaurenoids, taibairubescensins A and B, were isolated from the ethanol extract of the leaves and branches of Isodon rubescens. Their structures are designated as 2 beta,3 beta-diacetoxy-11 beta,13 alpha-dihydroxy-ent-kaur-16-en-15-one and 3 beta,11 beta-diacetoxy-2 beta,6 alpha-dihydroxy-ent-kaur-16-en-15-one, respectively, on the basis of detailed spsctroscopic analyses. (C) 2000 Elsevier Science Ltd. All rights reserved.