First-trimester prenatal diagnosis of hypophosphatasia: Experience with 16 cases

We have carried out first-trimester prenatal diagnosis of hypophosphatasia in 1 6 pregnancies with a 1 in 4 risk of this condition. The liver/bone/kidney isoenzyme of alkaline phosphatase was measured in chorionic villus samples using a specific monoclonal antibody and an enzymatic amplification system. Fifteen of the 16 pregnancies were correctly predicted, while one has been lost to follow up. We suggest that this assay system is likely to be superior to DNA-base methods for the first-trimester prenatal diagnosis of hypophosphatasia.     

Infantile hypophosphatasia: Successful prenatal assessment by testing for tissue-non-specific alkaline phosphatase isoenzyme gene mutations

We successfully assessed a fetus at risk for lethal infantile hypophosphatasia using amniocyte DNA and allele-specific oligonucleotide (ASO) probes for two missense mutations in the tissue-non-specific alkaline phosphatase isoenzyme (TNSALP) gene. The nucleotide changes had been discovered in a sister who died at 8 months of age from this inborn error of metabolism. The mother was known to carry the 747 (cDNA) G→A transition, whereas her husband and 5-year-old daughter, who were also healthy, carried the 1309 A→T transversion. Amniocytes, obtained at 16 weeks' gestation, provided genomic DNA for polymerase chain reaction (PCR) amplification of the appropriate TNSALP gene exons. ASO hybridization revealed absence of the 747A mutation and presence of the 1309T base change in the fetus, indicating a carrier for hypophosphatasia. At 8 months of age, the offspring was in excellent health and without any radiological evidence of skeletal disease. His serum ALP activity and plasma pyridoxal 5′-phosphate level were decreased and increased, respectively, at levels consistent with the prenatal assessment. The ASO studies were confirmed postnatally using peripheral blood leukocyte DNA. This is the first application of direct mutational analysis to assess a fetus at risk for hypophosphatasia.     

Activities of alkaline phosphatase in first trimester chorion biopsy tissue

We have determined the activity of alkaline phosphatase in chorionic villous tissue obtained in the first trimester of pregnancy, in order to obtain the normal range of values as a prerequisite for application to the prenatal diagnosis of the rare bone disease hypophosphatasia. The activities found were a combination of intestinal and liver/bone/kidney types; traces of placental type were present in only one sample.     

Prenatal diagnosis of infantile hypophosphatasia

Prenatal diagnosis was attempted in a pregnant Japanese woman whose son had died of infantile hypophosphatasia, using chorionic villi sampled at 10 weeks of gestation. Southern blot analysis of restriction fragment length polymorphism was used as a guide, with cDNA for the human liver-type alkaline phosphatase as a probe, and BclI as a restriction enzyme. The fetus was found to be a heterozygote; the pregnancy was allowed to continue; and the baby born was phenotypically normal.     

First-trimester diagnosis of hypophosphatasia. Importance of gestational age and of purity of CV samples

Prenatal diagnosis of hypophosphatasia was made by alkaline phosphatase (ALP) assay on a chorionic villous sample taken in the first trimester. Very low activities of the LBK isoenzyrnes indicated an affected fetus. Diagnosis was confirmed at 12 weeks of gestation by measurement of LBK isoenzyme activities in fetal bone tissue. In control chorionic villous samples an inverse relation was observed between LBK and placental ALP percentage during gestational age. High LBK ALP activities are observed in decidual tissue. Chorionic villous tissue must not be sampled after 12 weeks of gestation and decidual tissue must be excluded from the sample.     

Experimental investigation of the effect of sediment transport patterns on the adsorption of cadmium ions onto sediment particles

The mechanism of flow turbulence, sediment supply conditions, and sediment transport patterns that affect the adsorption of cadmium ions onto sediment particles in natural waters are experimentally simulated and studied in this study both in batch reactors and in a turbulence simulation tank. By changing the agitation conditions, the sediment transport in batch reactors can be categorized into bottom sediment-dominated sediment and suspended sediment-dominated sediment. It is found that the adsorption rate of bottom sediment is much less than that of suspended sediment, but the sediment transport pattern does not affect the final (equilibrium) concentration of dissolved cadmium. This result indicates that the parameters of an adsorption isotherm are the same regardless of the sediment transport pattern. In the turbulence simulation tank, the turbulence is generated by harmonic grid-stirred motions, and the turbulence intensity is quantified in terms of eddy diffusivity, which is equal to 9.84F(F is the harmonic vibration frequency) and is comparable to natural surface water conditions.When the turbulence intensity of flow is low and sediment particles stay as bottom sediment, the adsorption rate is significantly low, and the adsorption quantity compared with that of suspended sediment is negligible in the 6 h duration of the experiment. This result greatly favors the simplification of the numerical modeling of heavy metal pollutant transformation in natural rivers. When the turbulence intensity is high but bottom sediment persists, the rate and extent of descent of the dissolved cadmium concentration in the tank noticeably increase, and the time that is required to reach adsorption equilibrium also increases considerably due to the continuous exchange that occurs between the suspended sediment and the bottom sediment.A comparison of the results of the experiments in the batch reactor and those in the turbulence simulation tank reveals that the adsorption ability of the sediment, and in particular the adsorption rate, is greatly over-estimated in the batch reactor.     

Adsorption of phenolic compounds from aqueous solutions by aminated hypercrosslinked polymers

Two novel polymers （NJ-1 and N J-2） were synthesized by chemically modified a hypercrosslinked polymer NJ-0 with dimethylamine and trimethylamine, respectively. The comparison of the adsorption properties of the three polymers toward phenol, resorcin and phloroglucin was made. The study focused on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Freundlich equation was found to fit the adsorption results well. The effect of amino groups introduced onto the surface of the resin and the structure of phenolic compounds on the adsorption were also studied. The hydrogen-bonding interaction and electrostatic interaction could happen between the amino groups and the adsorbates. The adsorption impetus increased as quantity of hydroxyl groups increased, but the adsorption capacity decreased due to the drop of the matching degree of the aperture of resins and the diameter of adsorbate molecules.     

Composition analysis of colored dissolved organic matter in Taihu Lake based on three dimension excitation-emission fluorescence matrix and PARAFAC model, and the potential application in water quality monitoring

Taihu Lake is one of the five biggest lakes in China. Surface water samples from 26 sampling sites of Taihu Lake were collected. Furthermore wet chemical analysis （CODCr and BOD5） and measurement of three dimensional excitation-emission matrix （3DEEM） spectra in the laboratory have been conducted. Using parallel factor analysis （PARAFAC） model, three components of colored dissolved organic matter （CDOM） have been identified successfully, based on the analysis of 3DEEM data. The characteristics of the three components also have been described by comparing them to some components of CDOM, identified in earlier researches. Meanwhile, spatial variations of concentration for the three components in Taihu Lake have been analyzed, and the result indicates that the concentration of component 1 depends more on the situation of wastewater pollution and can be used as the indicator of wastewater pollution. The relationship between the concentrations of the three components and results of the wet chemical analysis show that none of the three components can be used as indicators of gross organic matter in water. However, the concentrations of all the three components have obvious linear relationships with the BOD5 value, especially for component 1 （r = 0.72878）. Finally, the potential applications of the composition analysis based on 3DEEM and PARAFAC model in water quality monitoring have been illuminated.     

汽车排气尾流中微粒分布及其变化特性的研究

根据微粒核化、凝并及凝结模型对汽车排气尾流中微粒分布的变化特性进行了分析.结果表明,微粒的核化增加了排气尾流中超细微粒的数量;微粒的凝并和凝结将改变排气尾流中的微粒分布.在核化、凝并及凝结过程同时存在时,核化对微粒分布的影响相对较小,微粒分布的变化主要受凝并和凝结的作用.在排气管出口处,微粒的核化、凝并及凝结过程比较剧烈,微粒分布变化较大;随着距排气管出口距离的增加,微粒演变逐渐减弱.研究工作可以为汽车排放控制策略的确定以及汽车微粒对人体健康影响的研究提供依据.     

北京市交通路口大气颗粒物污染特征研究(Ⅱ)——大气颗粒物中非烃类化合物污染特征

研究了北京市交通路口大气颗粒物中非烃类化合物的污染特征.通过对2000年6月采集的大气颗粒物样品的分析,研究了北京市崇文门路口大气颗粒物中非烃类化合物的污染状况.结果表明:交通排放是大气颗粒物中非烃类化合物的重要来源之一;总体上非烃类化合物主要富集在粒径较小的粒子中,细粒子中的非烃类化合物应主要来源于机动车尾气排放;白天ρ(非烃类化合物)随机动车流量的增加而增加,夜晚机动车流量减小,但ρ(非烃类化合物)却高于白天,显示出大型柴油车的主要影响和贡献;非烃类化合物的污染主要表现为酞酸酯和苯酚类化合物的污染.并对交通路口大气颗粒物中酞酸酯的来源进行了探讨.      

基于电子鼻土壤与地下水污染修复现场TVOC和恶臭的评估

根据上海某土壤与地下水污染修复现场情况,应用自主研发的电子鼻系统(iSA-M1)分别对未修复及修复过程中的土壤和地下水、修复场地上空及周边空气中的VOCs和恶臭类气体进行检测.结合前期研究所得TPI和OPI公式,求得各点的值,并将其用图表示.结果表明:①修复后TVOC和恶臭的浓度总体呈下降趋势;②在土壤和地下水修复过程中,VOCs和恶臭的挥发受气象要素和作业的影响,其浓度在总体下降的过程中伴随着阶段性上升现象;③结合GIS技术,电子鼻能初步用于评估土壤和地下水修复现场造成的空间污染情况及对周围居民产生的影响.但造成影响程度的具体细化分级还需要进一步研究.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

野生动物资源的保护与持续利用

本文从非洲南部的大象、澳大利亚的大袋鼠到北美的野生动物管理体制、欧洲的野生动物狩猎、新西兰草地牧业的转轨,回顾了世界野生动物利用与保护的历史。并追溯了我国古代野生动物管理思想,以黄羊、虎两个实例,分析了我国野生动物资源濒危的原因与现状。最后,探讨了野生动物资源保护与开发的辩证关系,提出了野生动物利用分为开发初期、过度开发期、保护恢复期及持续利用期,目前我国野生动物资源正处于保护恢复期。     

Effects of humic acid coatings on phenanthrene sorption to black carbon

Black carbon (BC) can strongly adsorb hydrophobic organic compounds (HOCs).The HOC sorption to coated BC could be attenuated in soil and sediment compared with that of the parent BC.To study the potential causes of the sorption attenuation,humic acid (HA) and BC were isolated.Phenanthrene (PHE) was selected as the representative of HOCs.BC was coated with the precipitated HA.The PHE sorption to the HA-coated BC was determined.The HA coatings on BC could result in the significant sorption attenuation of PHE to BC.The attenuation varied in different HA origin and was positively correlated to the aromaticity of HA.The attenuation could be explained by the direct competition between HA and PHE for the available sorption sites on BC and the reduction of the available sorption sites as a result of the pore blockage of BC caused by the HA coatings.Therefore,the HA coatings on BC was one potential cause of the attenuation of HOC sorption to BC in soil and sediment.     

Influence of lactic acid on the two-phase anaerobic digestion of kitchen wastes

To evaluate the influence of lactic acid on the methanogenesis, anaerobic digestion of kitchen wastes was firstly conducted in a two-phase anaerobic digestion process, and performance of two digesters fed with lactic acid and glucose was subsequently compared. The results showed that the lactic acid was the main fermentation products of hydrolysis-acidification stage in the two-phase anaerobic digestion process for kitchen wastes. The lactic acid concentration constituted approximately 50% of the chemical oxygen demand （COD） concentration in the hydrolysis-acidification liquid. The maximum organic loading rate was lower in the digester fed with lactic acid than that fed with glucose. Volatile fatty acids （VFAs） and COD removal were deteriorated in the methanogenic reactor fed with lactic acid compared to that fed with glucose. The specific methanogenic activity （SMA） declined to 0.343 g COD/（gVSS-d） when the COD loading were designated as 18.8 g/（L-d） in the digester fed with lactic acid. The propionic acid accumulation occurred due to the high concentration of lactic acid fed. It could be concluded that avoiding the presence of the lactic acid is necessary in the hydrolysis-acidification process for the improvement of the two-phase anaerobic digestion process of kitchen wastes.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

MFI型沸石吸附分离水体中混合硝基氯苯的研究

采用MFI型沸石(HZSM-5与Silicalite-1沸石)为吸附剂分别吸附水体中的对硝基氯苯和邻硝基氯苯,研究了温度与沸石的结构特性对硝基氯苯吸附的影响,以及2种硝基氯苯分子在MFI型沸石中的扩散行为．结果表明,在不同温度下,对硝基氯苯与邻硝基氯苯在HZSM-5与Silicalite-1沸石中的吸附行为明显不同;对硝基氯苯在2种MFI型沸石中的扩散系数都显高于邻硝基氯苯．对硝基氯苯与邻硝基氯苯在吸附量与扩散性上的差异导致HZSM-5与Silicalite-1沸石对对硝基氯苯的吸附具有良好的选择性．尤其HZSM-5沸石在低温下更有利于从水体中选择性吸附分离混合硝基氯苯。     

Spatial distribution of dissolved Pb, Hg, Cd, Cu and As in the Bohai Sea

Characteristics of the spatial distribution of selected dissolved heavy metals were analyzed during large scale surveys from August 12 to 25,2003 in the Bohai Sea.Dissolved Pb was the only element with average concentrations higher than the grade-one sea water quality standard of China.The spatial distribution of dissolved Pb in surface water was similar to those of Cd,Cu and As,where the isopleths generally indicated decreasing values from the bays to the central areas.Only for Hg did the high concentrations not only appear in Liaodong Bay,Bohai Bay and Laizhou Bay,but also in the Central Area,viz.not only in inshore but also in offshore areas. Vertical distributions of dissolved Pb,Cd,Cu and As were largely uniform,while that of dissolved Hg increased with depth.We infer that the input of pollutants from land was the main influencing factor for the detected distribution patterns of dissolved heavy metals, followed by the dynamics of sea water,release from bottom sediments and biochemical processes.Comparing with historical data, average concentrations of dissolved heavy metals appear to decline in recent years.     

北京市交通路口大气颗粒物污染特征研究(Ⅲ)——大气颗粒物中多环芳烃污染特征

研究了北京市典型交通路口大气颗粒物中多环芳烃的污染特征及影响因素.于2000年6月在北京市主要交通路口之一的崇文门路口采集大气中TSP,PM₁₀和PM_2.5样品,并进行样品中ρ(PAHs)的分析及机动车流量调查.研究结果表明:机动车排放是交通路口大气颗粒物中PAHs的首要来源;多环芳烃在粒径较小的粒子中比例较高;白天ρ(PAHs)随机动车流量的增加而增加,夜晚ρ(PAHs)高于白天;污染源识别表明,交通路口大气颗粒物中的多环芳烃除主要来源于机动车尾气排放外,还有一部分来源于道路扬尘.      

Sorption and cosorption of the nonionic herbicide mefenacet and heavy metals on soil and its components

Sorption and cosorption of the nonionic herbicide mefenacet and two typical metals (copper and silver) on black soil and its components (kaolinite and humic acid) were investigated. It was found that because of their different valences and properties, Cu²⁺and Ag⁺ presented different effects on the sorption of mefenacet. Due to the competition of Cu²⁺, along with the shells of dense water formed by its surface complexation, for sorption surface area with mefenacet, the addition of Cu²⁺ decreased the sorption amount of mefenacet on soil and its components, especially on humic acid. However, the addition of Ag⁺ significantly enhanced the sorption of mefenacet, which was attributed to the softness of the cation that weakened the hydrophilicity of the local region around Ag⁺-complexed functionalities, and thus mitigated the competitive sorption of water. In addition, the sorption of mefenacet on soil with or without the two metals was generally decreased with increasing pH, which was caused by the hydrolysis of carbonyl and carboxyl groups on the surface of the sorbents, π-π interaction between mefenacet and the soil organic matter, and so on. On the other hand, the presence of mefenacet seemed to have little effect on the sorption of Cu²⁺ and Ag⁺, indicating that Cu²⁺ and Ag⁺ might be sorbed strongly on the tested sorbents and the mefenacet added was too low in concentration to affect the sorption of the metals.