氢化物发生－原子荧光光谱法测定止痢散中三氧化二砷的含量

为完善止痢散质量标准,采用氢化物发生-原子荧光光谱法对止痢散中三氧化二砷的含量测定进行了研究。载流为3．0％盐酸溶液,还原剂为含0．5％氢氧化钾的1％硼氢化钾溶液,氩气载气流量为600mL／mL,砷空心阴极灯电流为60mA。砷元素进样浓度在0～100ng／mL范围内与荧光强度值呈良好的线性关系（r=0．9999）;样品平均回收率为95．3％（n=6）,RSD为1．9％。本方法简便、准确度高、重复性好,为进一步控制止痢散的质量提供了依据。     

液相色谱-串联质谱法测定水产品中孔雀石绿的残留量

建立了液相色谱-串联质谱测定水产品中孔雀石绿及其代谢物残留的检测方法。样品经乙酸铵盐溶液和乙腈提取,经二氯甲烷萃取,PRS阳离子交换柱净化,然后选用电喷雾离子源,在正离子、多反应监测方式模式下进行定性,以内标法进行定量。方法的检出限为0.10μg·kg-1,工作曲线的线性范围为0.10~4.00μg·kg-1。在添加浓度为0.10~4.00μg·kg-1的范围内,孔雀石绿和隐色孔雀石绿的平均回收率均分别为83.4%和95.0%,相对标准偏差分别为6.23%和6.74%。     

Hemoglobin and subunit multiplicity in the rainbow trout (Oncorhynchus mykiss) hemoglobin system

Hemoglobin (Hb) multiplicity is a commonly used index of phylogenetic differentiation and molecular adaptation in fish. Despite improvements in technologies for characterizing protein structure, our knowledge of the component composition of the Hb system in rainbow trout, Oncorhychus mykiss, has remained almost unchanged through three decades. The Hb is considered to consist of four components, of which two (HbI and HbIV) have been extensively characterised with regard to structure and function. Using a variety of molecular techniques we demonstrate the presence of at least nine different Hb fractions composed of nine (five α and four β globin) chains, and that HbI and HbIV consist of two and five individual components, respectively. These findings indicate that the published data on trout HbI and HbIV refer to mixtures of isoHbs and need to be reappraised. This revised version was published online in August 2006 with corrections to the Cover Date.     

Discrimination of the natal origin of young-of-the-year Allis shad (Alosa alosa) in the Garonne–Dordogne basin (south-west France) using otolith chemistry

Abstract –  The otolith composition of age 0+ Allis shad ( Alosa alosa ) captured in two rivers in the Gironde system in south-west France, the Dordogne and the Garonne, was analysed to establish the natal origin of the fish. Inductively coupled plasma mass spectrometry analyses were used to take measurements of 15 isotopes, among which Co, Fe, Sr and Rb were the most important elements in the discrimination process. It was possible to reclassify each sampled fish into its natal river basin (Garonne or Dordogne) with a high degree of accuracy. Linear discriminant analysis correctly reclassified 91.1% of the Garonne samples and 87.8% of the Dordogne samples (mean success in reclassification in 20 runs ± 1 SD: 89.21 ± 8.6%). Artificial neural networks correctly reclassified 90.1% of the Garonne samples and 81.2% of the Dordogne samples (mean success in reclassification after 1000 training cycles ±1 SD: 85.6 ± 9.1%). Using these tools the present results show that it is possible to assign a natal origin to juvenile shad that hatched in the Dordogne–Garonne basin based on the trace elements in the otolith.     

Endotoxin Structures in the Psychrophiles Psychromonas marina and Psychrobacter cryohalolentis Contain Distinctive Acyl Features

Lipid A is the essential component of endotoxin (Gram-negative lipopolysaccharide), a potent immunostimulatory compound. As the outer surface of the outer membrane, the details of lipid A structure are crucial not only to bacterial pathogenesis but also to membrane integrity. This work characterizes the structure of lipid A in two psychrophiles, Psychromonas marina and Psychrobacter cryohalolentis, and also two mesophiles to which they are related using MALDI-TOF MS and fatty acid methyl ester (FAME) GC-MS. P. marina lipid A is strikingly similar to that of Escherichia coli in organization and total acyl size, but incorporates an unusual doubly unsaturated tetradecadienoyl acyl residue. P. cryohalolentis also shows structural organization similar to a closely related mesophile, Acinetobacter baumannii, however it has generally shorter acyl constituents and shows many acyl variants differing by single methylene (-CH₂-) units, a characteristic it shares with the one previously reported psychrotolerant lipid A structure. This work is the first detailed structural characterization of lipid A from an obligate psychrophile and the second from a psychrotolerant species. It reveals distinctive structural features of psychrophilic lipid A in comparison to that of related mesophiles which suggest constitutive adaptations to maintain outer membrane fluidity in cold environments.     

微波消解-石墨炉原子吸收光谱法测定人参中铅和镉

目的建立一种快速准确的微波消解-石墨炉原子吸收光谱法测定人参中铅和镉的含量。方法采用微波消解对样品进行前处理,应用石墨炉原子吸收光谱法测定人参中铅和镉的含量。结果铅在0μg/L~40μg/L范围,镉在0μg/L~3μg/L范围具有良好的线性,相关系数均大于0.999,检出限分别为3.6μg/kg和0.42μg/kg,相对标准偏差(RSD)为9.11%和4.70%,加标回收率在93.3%~106.7%之间。结论该方法简便快速、准确灵敏,适用于测定人参中铅和镉的含量。     

铁皮石斛枫斗加工前后差异成分比较

铁皮石斛(Dendrobium officinale Kimura et Migo)的传统功效为益胃生津、滋阴清热,在降血糖方面具有较好的作用。前期研究发现,与铁皮石斛鲜条相比,枫斗的α-葡萄糖苷酶抑制率更高,且枫斗中化学成分种类丰富。为明确铁皮石斛枫斗与鲜条的差异性成分,阐明铁皮石斛加工成枫斗的科学内涵,本研究利用超高效液相色谱-四级杆串联飞行时间质谱仪(UPLC-QTOF-MS)在正离子模式下采集二者的代谢物信息,通过主成分分析、偏最小二乘判别分析等算法挖掘差异性化合物,并利用质谱碎片、数据库比对等方式鉴定差异性成分,最后采用聚类分析方法研究差异性成分在铁皮石斛枫斗和鲜条中的含量变化规律。经过筛选和鉴定共得到16种差异性化合物,其中柚皮素、4,4'-二羟基-3,5-二甲基联苄、诺比林A、石斛酚等12种黄酮、联苄类化合物在枫斗中含量较高,而α-亚麻酸、L-苯丙氨酸、草质素等4种脂肪酸、氨基酸类化合物在鲜条中含量较高,这些差异性成分可能是潜在的铁皮石斛枫斗降血糖功能成分。本研究结果为阐明铁皮石斛枫斗降血糖物质基础提供了数据支撑,对进一步促进铁皮石斛精深加工具有重要意义。     

兽用止痢、止泻中草药制剂的质量检测及制备(英文)

[目的]制订止痢、止泻兽用中草药制剂的质量检验标准。[方法]分别采用理化鉴别和紫外分光光度计的定性检测对比试验。[结果]蒸馏水法检测的最大吸收峰峰值相差大于1 nm;0.9%盐酸法和60%乙醇法得出最大吸收峰的峰值相差小于1 nm,次吸收峰的峰值差别也均小于1 nm。[结论]选用0.9%盐酸法和60%乙醇法作为兽用止痢、止泻中草药制剂的质量检测标准。     

微孢子虫糖蛋白的研究进展

随着蛋白质组学和糖组学研究的迅速发展,糖蛋白已成为众多研究的中心.糖蛋白的糖链结构直接影响其功能,因此糖蛋白中糖链的结构研究成为糖生物学研究的重点之一.就糖蛋白研究的基本策略方法作了简要介绍,并且简要概括了近年来微孢子虫糖蛋白的研究进展.     

石墨炉原子吸收法测定河流中重金属铅的含量

[目的]对贵州省六冲河的重金属铅污染情况进行评价。（方法]使用石墨炉原子吸收法对贵州省六冲河3个采样布设点的水质进行分析,测定其中的铅含量。[结果]六冲河重金属铅测定的加标回收率为99．67％～103．30％,RSD为0．8～1．8,3个采样点水中铅含量分别为2．93、2．86和2．76μg/L。[结论]六冲河的重金属铅含量较低,但今后仍应当防止铅含量超标引起河流污染。