改性树脂NKZ对水溶性染料的吸附特性研究

根据聚合物絮凝剂与染料相互作用机理,用硝基胍对大孔型氯球改性得到了功能化吸附树脂NKZ.从热力学和动力学两方面研究了该树脂对5种水溶性染料的静态吸附特性.结果表明,树脂NKZ对水溶性染料的吸附具有很好的效果.     

泥石流与人类经济活动

山地是泥石流与人类共存的环境,泥石流作用于山地环境,强烈地影响人类经济活动：人类经济活动也作用于山地环境,强烈地影响泥石流。泥石流对山地环境的危害,主要为破坏地表、破坏生态系统和淤堵江河;泥石流对人类及其经济活动的危害,主要为破坏城镇,村庄,工矿,交通水利水电工程,农田和人类自身的安全。泥石流危害的结果,能导致山地坡面破碎化、沟口沙石化、河床宽浅化和植被逆向演替化,以及耕地贫瘠化、经济发展滞后化和     

Increase in biodegradation of dimethyl phthalate by Closterium lunula using inorganic carbon

The effect and mechanism of inorganic carbon (IC) on the biodegradation of dimethyl phthalate (DMP) by a green microalga Closterium lunula was investigated. The growth of this microalga and the biodegradation of DMP were significantly enhanced when the initial IC was increased. An intermediate product of DMP biodegradation was identified as phthalic acid (PA) that was accumulated and caused a sharp decrease in pH of microalgal culture medium, which inhibited both the growth of microalga and the biodegradation of DMP. A suggested second-order kinetic equation of organic pollutant biodegradation by microalgae (-dC/dt = kNr) fitted well with the experimental data. The increase of IC caused a decline in biodegradation rate constant for organic carbon (k) and an increase in growth (N) by supplying a favorite carbon source and mitigating the decrease of pH. As the net effect, the overall biodegradation rate of DMP was promoted as IC increased, which was dominated by the increase of microalgal growth.     

如何浅开谈展石环油境石应化企急工业作

根据石化企业环境应急工作面临的任务和国内外发展趋势,对企业的环境应急现状和存在问题进行了分析和评价,论述了开展环境应急工作的必要性和紧迫性,探讨了石化企业开展环境应急工作的指导思想和方法。     

Nitrogen removal from landfill leachate via ex situ nitrification and sequential in situ denitrification

Ex situ nitrification and sequential in situ denitrification represents a novel approach to nitrogen management at landfills. Simultaneous ammonia and organics removal was achieved in a continuous stirred tank reactor (CSTR). The results showed that the maximum nitrogen loading rate (NLR) and the maximum organic loading rate (OLR) was 0.65 g N l^?1 d^?1 and 3.84 g COD l^?1 d^?1, respectively. The ammonia and chemical oxygen demand (COD) removal was over 99% and 57%, respectively. In the run of the CSTR, free ammonia (FA) inhibition and low dissolved oxygen (DO) were found to be key factors affecting nitrite accumulation. In situ denitrification was studied in a municipal solid waste (MSW) column by recalculating nitrified leachate from CSTR. The decomposition of MSW was accelerated by the recirculation of nitrified leachate. Complete reduction of total oxidized nitrogen (TON) was obtained with maximum TON loading of 28.6 g N t^?1 TS d^?1 and denitrification was the main reaction responsible. Additionally, methanogenesis inhibition was observed while TON loading was over 11.4 g N t^?1 TS d^?1 and the inhibition was enhanced with the increase of TON loading.     

The fragmentation patterns of maternal plasma cell-free DNA and its applications in non-invasive prenatal testing

The discovery of cell-free DNA (cfDNA) in maternal plasma has opened up new promises for the development of non-invasive prenatal testing (NIPT). Application of cfDNA in NIPT of fetus diseases and abnormalities is restricted by the low amount of fetal DNA molecules in maternal plasma. Fetus-derived cfDNA in maternal plasma are shorter than maternal DNA, thus leveraging the maternal and fetus-derived cfDNA molecules size difference has become a novel and more accurate method for NIPT. However, multiple biological properties such as size distribution of plasma DNA, proportion of fetal-derived DNA and methylation levels in maternal plasma across different gestational ages still remain largely unknown. Further insights into the size distribution and fragmentation pattern of circulating plasma cfDNA will shed light on the origin and fragmentation mechanisms of cfDNA during physiological and pathological processes in prenatal diseases and enhance our ability to take the advantage of plasma cfDNA as a molecular diagnostic tool. In the review, we start by summarizing the research techniques for the determination of the fragmentation profiles of cfDNA in maternal plasma. We then summarize the main progress and findings in size profiles of maternal plasma cfDNA and cffDNA. Finally, we discuss the potential diagnostic applications of plasma cfDNA size profiling.     

Discordant results between fetal karyotyping and non-invasive prenatal testing by maternal plasma sequencing in a case of uniparental disomy 21 due to trisomic rescue

Uniparental disomy (UPD) is an uncommon chromosome condition, but UPD involving chromosome 21 is rarely reported. We reported here a case who had first trimester screening test for Down syndrome, chorionic villus sampling for fetal karyotyping, quantitative fluorescence polymerase chain reaction (QF-PCR), as well as non-invasive prenatal testing (NIPT) by maternal plasma sequencing. There were discordant results between fetal karyotyping and NIPT due to UPD 21combined with confined placental mosaicism of trisomy 21. This demonstrated that it is possible to detect placental mosaicism by NIPT, but further studies are required to confirm its sensitivity. Therefore, all positive NIPT results must be confirmed by conventional invasive test and karyotyping. QF-PCR has the additional benefit in diagnosing UPD. © 2013 John Wiley & Sons, Ltd.