Prenatal diagnosis in two cases of de novo complex balanced chromosomal rearrangements. Three-year follow-up in one case

We report two cases of apparently balanced complex de novo chromosomal rearrangements (BCCR) detected prenatally at 17 weeks and 10 weeks of gestation, respectively. Chromosomes were studied using GTG-banding and fluorescent in situ hybridization (FISH). In one case four chromosomes and in the other case three chromosomes were involved in the rearrangements. One of the pregnancies was terminated and no external or internal abnormalities were detected at autopsy. The other pregnancy continued to term. Level III ultrasound examination showed no abnormalities. The child is now 3 years old and has neither congenital anomalies nor evidence of delayed psychomotor development.     

Prenatal diagnosis of β thalassaemia by reverse phase HPLC

Reverse phase HPLC of radioactive globin chains has been compared to classical carboxy methyl cellulose chromatography for the prenatal diagnosis of β thalassaemia. The two methods correlated highly (r = 0.97 p < 0.0005) and provided an identical diagnosis for 40 fetal blood samples of fetuses homozygous or heterozygous for β thalassaemia. The HPLC procedure was much faster and required fewer biochemical steps (no globin preparation). It was at least as accurate and more sensitive than the classical chromatography. A single column can be used for 150 analyses and is always ready to be used. Last but not least it is much less expensive than CMC chromatography.     

兰炼烷基化废酸处理工艺选择

对目前四种烷基化硫酸处理工艺进行了分析比较，认为兰炼应依托现有硫酸装置，采用裂解制硫酸工艺来处理烷基化废酸。     

钻井泥浆和消油剂对合浦珠母贝的急性毒性效应

采用96h急性毒性试验配合滤食率和微核检测等方法，比较了石油勘探开发用3种钻井泥浆和3种消油剂对合浦珠母贝成贝急性毒性效应。实验结果表明：3种钻井泥浆对合浦珠母贝的半致死浓度均大于10^5mg/L；3种消油剂的半致死浓度分别为1047、5011和2630mg/L；滤食率与钻井泥浆和消油剂的浓度呈负相关；微核细胞率则与之呈正相关。     

镉对沉水植物硝酸还原酶和超氧化物歧化酶活性的影响

研究了重金属污染物镉对４种沉水植物（红线草，金鱼藻，黑藻和菹草）硝酸还原酶和超氧化物歧化酶的分子毒理学效应。实验结果表明，一定浓度的镉能诱导沉水植物的硝酸还原酶活性，抑制沉水植物超氧化物歧化酶活性，从而破坏其抗氧化防御系统。镉对沉水植物的毒害存在明显的剂量／效应关系。建议以硝酸还原酶和超氧化物歧化酶的活性变化作为沉水植物受重金属污染的生态毒理学指标。     

Acid resistance of methanogenic bacteria in a two-stage anaerobic process treating high concentration methanol Wastewater

In this study, the two-stage upflow anaerobic sludge blanket (UASB) system and batch experiments were employed to evaluate the performance of anaerobic digestion for the treatment of high concentration methanol wastewater. The acid resistance of granular sludge and methanogenic bacteria and their metabolizing activity were investigated. The results show that the pH of the first UASB changed from 4.9 to 5.8 and 5.5 to 6.2 for the second reactor. Apparently, these were not the advisable pH levels that common methanogenic bacteria could accept. The methanogenic bacteria of the system, viz. Methanosarcina barkeri, had some acid resistance and could still degrade methanol at pH 5.0. If the methanogenic bacteria were trained further, their acid resistance would be improved somewhat. Granular sludge of the system could protect the methanogenic bacteria within its body against the impact of the acidic environment and make them degrade methanol at pH 4.5. The performance of granular sludge was attributed to its structure, bacteria species, and the distribution of bacterium inside the granule. Translated from Acta Scientiae Circumstantiae, 2004, 24(4): 633–636 [译自: 环境科学学报]