四氯乙烯替代四氯化碳作为油类萃取剂的研究

油类萃取剂四氯化碳对人体毒性较大，且对大气臭氧层有着严重的破坏作用。实验尝试用低毒的四氯乙烯替代四氯化碳作为油测定的萃取剂。经两者在检出限、线性、精密度、质控样品测定，以及萃取效率试验、加标回收试验的比较。结果表明：改进方法代替标准方法基本可行。四氯乙烯较之其他替代品具有一定的优越性。     

Prenatal diagnosis of trisomy 4p: a new locus for holoprosencephaly?

Trisomy of the short arm of chromosome 4 is a well-known syndrome, and several observations have been made in the last 30 years. Herein, we report a new observation of trisomy 4p in a fetus with a semi-lobar holoprosencephaly (HPE), dysmorphic features and multiple malformations. The diagnosis of HPE was made, at 33 weeks' gestation, on the fetus of a healthy G1P0 woman. Amniocentesis was performed for chromosome analysis and additional material was found on a chromosome 22. The couple elected to terminate the pregnancy and fetal examination was realized. Conventional and molecular cytogenetic studies were performed on the fetus and the parents, which showed that the additional material found on one chromosome 22 corresponded to the short arm of chromosome 4 and therefore led us to establish a diagnosis of trisomy 4p inherited from the malsegregation of a paternal translocation t(4;22)(q12;q11.1). The etiology of HPE is very heterogeneous; it includes non-genetic factors such as maternal diabetes and genetic causes. HPE cases have been described in association with many chromosomal anomalies, trisomy 13 being the most frequent. However, to our knowledge, HPE has never been previously reported in association with a trisomy involving solely the short arm of chromosome 4. Copyright © 2005 John Wiley & Sons, Ltd.     

黄曲霉A5p1脱色类黑精及其机理初探:葡萄糖氧化酶的作用

类黑精是一种高分子难降解色素污染物质,在糖蜜酒精废水中大量存在.选取在前期研究中对糖蜜酒精废水具有较好脱色作用的黄曲霉(Aspergillus flavus)A5p1(保藏号CGMCC.4292),以合成的类黑精为对象研究脱色机理,试图为实际废水的生物脱色提供理论基础.结果显示,此菌株对合成类黑精具有生物吸附和生物降解的双重作用,以后者为主,最高脱色率可达65%.相较于漆酶、依赖/不依赖于锰的过氧化物酶等常规氧化脱色酶,此菌株中的产过氧化氢酶对脱色起主要作用,而且脱色过程中作为产过氧化氢酶之一的葡萄糖氧化酶与类黑精脱色率之间存在着一定的正相关性.添加葡萄糖氧化酶激活剂和抑制剂进行验证,发现葡萄糖氧化酶酶活力、过氧化氢产量和脱色率三者之间呈相关性变化.初步推测,葡萄糖氧化酶是黄曲霉A5p1生物降解脱色类黑精的关键酶之一.     

从废催化剂中回收钼的新工艺

确定了用新型复合浸取剂从废催化剂中回收钼的最佳工艺条件废催化剂颗粒度１００目焙烧温度７５０℃,焙烧时间１ｈ复合浸取剂中助浸剂质量为５％,浸取固液质量比１：３,浸取温度６０℃,浸取时间６ｈ,在该条件下,钼的浸取率达到９２．７％～９５．５％。     

The Quality of Water in the Buško Blato Reservoir

The article presents the results of chemical andmicrobiological measurements of the water quality in theBuko Blato reservoir, the largest in Europe, in the period 1989 to 1998.The aim was to observe possiblechanges in water quality during the past decade and itsinfluence on the downstream section of the Cetina River andits numerous tributaries and reservoirs, where there are twolarge regional water supply systems. This reservoir wasbuilt in order to exploit the high hydro-electric potentialof small streamflows in the karst fields of south-westernBosnia. It has strongly influenced the hydrologicconditions of the downstream section of the Cetina River.Buko Blato is a relatively shallow reservoir with the meandepth of 5 m. It covers an area of 57 km². The waterexchange in the reservoir is slow, occurring from one toseveral years. When the water inflow exceeds the hydroelectric plant demands the excess water is delivered by a reversible channel and pre-pumped into the Buko Blato reservoir. The total and carbonate water hardness in thereservoir is lower than in the Cetina River and in typicalkarst streamflows, since the water in this reservoir comesmainly from surface sources including numerous springs withhigh capacity oscillations, torrents and rainfall.Measurements, carried out during the past years, showed asignificant increase in nitrate content as well as in thecoli bacteria and a less significant increase in totalphosphorus content. The water quality was evaluated asmezotrophic according to the total phosphorus content basedon the Carlson index of trophic level, a lower quality thanin the Perua reservoir, upstream on the Cetina River. Thelatter contains a smaller phosphorus content and wasclassed between oligotrophic and mezotrophic. According tothese data, employing the Vollenweider equation, the totalphosphorus content in this water should not exceed the meanof 20 mg m^-3 P. The results indicate that the water inthe Buko Blato reservoir did not deteriorate the waterquality on the downstream section of the Cetina River.     

斑马鱼p53基因结构比对分析及其在生态毒理学中的应用

斑马鱼p53基因由11个外显子和10个内含子组成,外显子1和外显子11部分序列不参与编码蛋白质．其 cDNA核苷酸序列共2089bp,包含一个1122 bp的开放阅读框(Open Reading Frame,ORF)(44 bp-1165 bp),这个 ORF编码373个氨基酸．另外在3’端有924 bp是非翻译区(3’-UTR),5’端同样也存在43 bp的非翻译区(5’- UTR);12种脊椎动物p53氨基酸序列的保守性分析结果表明,在一些特殊的区域,12种氨基酸序列表现出了很高的保守性,这些区域和p53的抑癌功能密切相关．研究结果预示斑马鱼p53基因是一种理想的环境致突变物研究分子模型,在生态毒理学研究中具有良好的应用前景．     

Comparison of refrigerated warehouse energy demand with R-717 and R-507 using eQUEST model

Natural refrigerant ammonia R-717 and synthetic azeotropic refrigerant R-507 (a blend containing 50% R-143a and 5% R-125 by weight) are used in a wide range of refrigeration systems especially in low-temperature applications. R-717 and R-507 are ozone friendly refrigerants, which have no Ozone Depletion Potential (ODP). Global Warming Potential (GWP) of R-717 and R-507 is equal to zero and 3300, respectively. The high amount of R-507 GWP demonstrates its negative effect on the Earth’s climate change. In this study, a refrigerated warehouse located in Cincinnati, Ohio was modeled and the total energy demand and Coefficient of Performance (COP) was evaluated by eQUEST using two scenarios. The R-717 and R-507 were used as refrigerant in the first and second scenarios, respectively. The results showed that using R-717 in the refrigeration system leads to a 15% energy saving and a higher COP compared to R-507 in all working conditions. The only exception is that at an evaporating temperature below ?35°C which COP values of both refrigerants are approximately equal.