洛阳市大气污染特征与相关气象要素24小时变化分析

通过对洛阳市环境空气监测资料的统计,归纳出洛阳市区日内24小时环境空气污染变化特征,并结合同步气象观测资料综合分析,找出了二者之间的联系特征。引入气温日较差这一便于观测、预报的气象要素表征空气污染物垂直扩散特征,为今后进行污染预报提供了新的思路。     

火焰原子吸收测定土壤中的铜

采用硝酸-盐酸-高氯酸代替传统的消解方法分解土壤样品,火焰直接喷入原子吸收法测定土壤中的铜。相对标准偏差为0.6％～3.5％,加标回收率97.5％～101％。     

Enrichment of fetal cells from maternal blood by high gradient magnetic cell sorting (double MACS) for PCR-based genetic analysis

For simple and effective isolation of fetal cells from peripheral maternal blood, we combined depletion of maternal cells and enrichment of fetal cells by high-gradient magnetic cell separation (MACS). First CD45⁺ and CD14⁺ cells were depleted from maternal peripheral blood mononuclear cells by MACS. From the depleted fraction, CD71⁺ erythroid cells were enriched up to 80 per cent by MACS. This ‘double-MACS’ procedure yielded an average depletion rate of 780-fold and an average enrichment rate of 500-fold, with approximate recovery rates of 40–55 per cent. For paternity testing, cells from unseparated blood and the various fractions were analysed for polymorphism of the HLA-DQ-A1 locus and D1S80 locus by the polymerase chain reaction (PCR). In CD45⁻/CD71⁺ sorted cells from maternal blood, but not in unfractionated cells from maternal blood or CD45⁻/CD14⁻ cells, paternal alleles could be detected. In the CD45⁻/CD71⁺ fraction, the relative frequency of paternal alleles compared with maternal alleles ranged from 1 in 20 to 1 in 200 (determined by titration and depending on the quality of separation and biological variation). In 7 out of 11 cases, between weeks 12 and 25 of gestation, we could identify paternal alleles by PCR, either HLA-DQ-A1 or D1S80. This double-MACS procedure is simple, fast, efficient, and reliable for non-invasive prenatal diagnosis.     

Study on an environmental-friendly and high-efficient fuel cell energy conversion system

The kinds and the distribution of the coal in China are investigated.The results indicated that the 80% coal in China is used by the method of the coal gasification.The possibility of utilization and development of the fuel cell power plant in China is analyzed.A combined cycle generation system is designed.Its net electrical efficiency is about 55%(LHV),which is higher than that of the fire power plant.So it is environmental-friendly and high-efficient generation mode.     

Enrichment of fetal nucleated cells from maternal blood: Model test system using cord blood

The presence of small numbers of fetal nucleated red cells in the maternal circulation has been a stimulus for the development of technologies for non-invasive prenatal genetic analysis. Our laboratory has been assessing the feasibility of density gradient centrifugation followed by magnetic activated cell sorting (MACS) of cells expressing CD32 and CD45, to deplete maternal nucleated blood cells. We have examined the efficiency of each of the steps of this procedure using cord blood from term pregnancies as a source of nucleated red blood cells. Cord blood was shown to contain highly variable numbers of nucleated red cells. Three different density gradients were examined. There was no major difference in the performances of the double and triple gradients. Density gradient centrifugation resulted in enrichments of nucleated red blood cells of about 1000-fold relative to the total cell count. However, it was apparent that the selection of the cell layers which were most enriched for these cells would result in significant losses of nucleated red cells in other layers. MACS sorting of cells using CD45 resulted in white cell depletions ranging from 7 to 34-fold. These data provide a foundation for comparison with other methods and for optimization of the MACS technique.     

Prenatal diagnosis by in situ hybridization on uncultured amniocytes: Reduced sensitivity and potential risk of misdiagnosis in blood-stained samples

Maternal cell contamination was assessed in 18 macroscopically blood-stained amniotic fluid samples from male fetuses. The samples were analysed by double-target fluorescent in situ hybridization (ISH) with Y and X chromosome-specific probes. The only sample with an aberrant karyotype (47, XY, +18) was also analysed by hybridization with a chromosome 18-specific probe. An interpretation of extensive maternal cell contamination was made in two samples, one of which was the sample with trisomy 18. ISH with the chromosome 18-specific probe on this latter sample showed that the sensitivity of the ISH method for chromosome enumeration of uncultured amniotic fluid samples may be reduced in bloodstained samples. It was calculated that by using ISH for chromosome enumeration of the two extensively contaminated samples, a case of trisomy 21 might have been overlooked in both samples, while a case of trisomy 18 might only have been overlooked in one of the samples. It is concluded that ISH should not be used for chromosome enumeration of uncultured amniotic fluid samples that are macroscopically blood-stained without further technical developments.     

铅诱导的PC12细胞凋亡及caspase-3的激活

用MTT法及TUNEL法检测醋酸铅对PC12细胞活力和凋亡率的影响,并用荧光标记的特异性caspase-3抑制剂来测量caspase-3的激活.结果显示,PC12细胞暴露于浓度为0.1、1、10、100 μmol·L-1的醋酸铅中24 h后,凋亡率和caspase-3的激活显著增加,并具有剂量-效应关系;当铅浓度达到1 μmol·L-1及以上时,细胞活力明显下降.因此可以推论,铅能够诱导PC12细胞发生凋亡,caspase-3的激活可能在这过程中起了非常重要的作用.     

Normal ranges of the activities of ten different enzymes in 100 independent preparations of chorionic villi. Comparison of specimens from induced abortions,biopsies, and cultured cells

In order to obtain a large set of normal control values, the activities of three cytosolic enzymes of purine metabolism and seven lysosomal enzymes were determined in homogenates of chorionic villi derived from induced abortions of normal pregnancies (7th–12th week) in about 100 individual cases. Possible reasons for the rather wide ranges of normal distributions of enzyme activities are discussed. The values are compared: (1) with available data in the literature; (2) with activities determined in decidual homogenates prepared from the same samples; (3) with activities of cells of cultures established and grown from villi in the same samples; and (4) with enzyme activities measured in chorionic biopsies using the same methods. Implications for the prenatal diagnosis of the associated metabolic diseases are considered.     

Effects of some heavy metals on cell suspension cultures of Catharanthus roseus

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Effects of exogenous Ca2+ on the membrane permeability, MDA and SH group content of Alexandrium sp. LC3 under surfactant stress

The effect of Ca^2 on the removal of Alexandrium sp. LC3 under HDTMAB stress was investigated. The results showed that thetoxic effect of HDTMAB on Alexandrium sp. LC3 was significantly reduced in the presence of Ca^2 , especially under 4 mmol/L of Ca^2 .To understand the underlying mechanism, the SH group and MDA content of the cell membrane and membrane permeability weremeasured. It was found that the SH content of cell member increased, the MDA content and membrane permeability decreased whenAlexandrium sp. was treated with Ca^2 and HDTMAB complex, compared with using HDTMAB only. The data suggested that Ca^2 mightpromote HDTMAB stress resistance of Alexandrium sp. LC3 by reducing the permeability and increasing the stability of cell membrane.