Prenatal diagnosis of Hb H disease due to compound heterozygosity for South-East Asian deletion and Hb constant spring by polymerase chain reaction

A pregnant woman has two children affected by moderately severe Hb H disease due to compound heterozygosity of South-east Asian deletion and Constant Spring mutation. In her third pregnancy, transabdominal chorionic villus sampling was performed at the tenth gestational week to obtain fetal DNA. The polymerase chain reaction was used for detection of both the South-east Asian deletion and the Constant Spring mutation. Hb H disease was diagnosed in the fetus. After genetic counselling, the couple elected to have the pregnancy terminated.     

近40年长江中下游春季低温气候特征及影响研究

本文研究了近40a来我国长江中下游地区春季低温的气侯特征,同时给出了研究低温的定量指标,并就低温对早稻产量的影响进行了初步探讨。     

春节期间烟花爆竹燃放对海口市空气质量的影响

基于2018年与2019年春节期间常规空气污染物数据、2019年细颗粒物PM_2.5中水溶性离子和OC/EC的化学组分数据，结合气象资料，分析了春节期间烟花爆竹燃放对海口市空气质量的影响。结果表明：春节期间烟花爆竹燃放对海口市初一的空气质量影响较大，主要影响污染物为PM₁₀、PM_2.5和SO₂，对NO₂、CO和O₃影响相对较小；实施烟花爆竹严格管控后空气质量明显改善，2019年除夕夜PM₁₀、PM_2.5和SO₂质量浓度峰值较2018年分别下降67.4%、68.5%和66.7%；烟花爆竹集中燃放主要造成K⁺、Cl^-、Mg²⁺和SO₄^2-快速上升，其中K⁺影响最为显著，K⁺短时上升了16.21 μg/m³，增加17.01倍；对于NO₂^-、Na⁺、F^-、NO₃^-、Ca²⁺、NH₄⁺等6种离子和OC/EC影响较小。     

Physiological and biochemical responses of Microcystis aeruginosa to phosphine (PH3) under elevated CO2

Phosphine (PH₃) is an important factor driving the outbreak of cyanobacterial blooms that produce toxic microcystin threating human health. To clarify the physiological and biochemical responses of cyanobacteria to PH₃ under elevated CO₂ concentration, Microcystis aeruginosa was used in the coupling treatment of 1000 ppmv CO₂ and PH₃ at different concentrations respectively. The chlorophyll a (Chl-a), carotenoid, net photosynthetic rate and total protein of M. aeruginosa exhibited evidently increasing tendency under the coupling treatment of 1000 ppmv CO₂ and PH₃ at different concentrations (7.51 × 10^?3, 2.48 × 10^?2, 7.51 × 10^?2 mg/L). The coupling treatments resulted in the higher concentrations of Chl-a and carotenoid of M. aeruginosa, compared to those in the control and the treatment with CO₂ alone, and their enhancement increased with the increase in PH₃ concentrations. The total antioxidant capacity (T-AOC) in the coupling treatment with CO₂ and PH₃ of 2.48 × 10^?2 mg/L and 7.51 × 10^?3 mg/L showed increasing tendency, compared to the treatment with PH₃ alone. Additionally, the coupling treatment with 1000 ppmv CO₂ and PH₃ also altered the pH and DO level in the culture medium. In this regard, the coupling treatment with CO₂ and PH₃ at an appropriate concentration can enhance the resistance of M. aeruginosa to PH₃ toxicity and is beneficial to the reproduction of M. aeruginosa, presumably resulting in potential for the outbreak of cyanobacteria bloom. Given the concern about global warming and the increase in atmospheric CO₂ level, our research laid a foundation for the scientific understanding of the correlation between PH₃ and cyanobacteria blooms.     

巢湖流域氮磷面源污染与水华空间分布遥感解析

基于遥感监测手段,分别应用DPeRS模型和MODIS水华提取方法对巢湖流域氮磷面源污染特征和巢湖水体水华爆发规律进行遥感像元尺度解析,结果表明: 2010年巢湖流域总氮产生量为1900.3t,入河量为846.5t;总磷为244.1t,入河量为76t.巢湖流域农业面源污染对氮素污染贡献最大,而水土流失则对磷面源污染贡献最大;综合巢湖流域氮磷面源污染和水华爆发的时空特征分析,明确氮磷面源污染与巢湖水华具有相关性,并且时间上水华爆发频率较氮磷面源污染具有先滞后后同步的特征,且面源污染负荷与水华爆发面积的相关系数为0.45;在空间上,面源污染负荷较大区域与水华爆发频度较高区域也有较好的匹配性;基于这种相关性,应用DPeRS模型对巢湖流域进行氮磷减排情景分析,结果表明在施肥量减少30%,农村生活垃圾处理率提高到60%,畜禽粪便处理率和城市垃圾处理率提高到80%的情况下,氮磷面源污染平均削减率可以达到50%.     

2011年春季东海赤潮演替过程中海水中的游离态多胺

利用高效液相色谱法测定了2011年东海赤潮演替过程中海水中的主要的游离态多胺腐胺、亚精胺和精胺的浓度.调查海区腐胺、亚精胺和精胺的浓度范围分别为0~48nmol/L,3~11nmol/L和2~17nmol/L,其中腐胺的平均浓度最高,亚精胺次之,精胺的浓度最低.从平面分布看,在4月份以中肋骨条藻为主的硅藻赤潮爆发期,和5月份以东海原甲藻为主的甲藻赤潮爆发期,赤潮爆发的区域多胺浓度相对较高;各个断面的多胺浓度随着赤潮爆发的过程发生变化,并且与DOC、POC、DON以及C/N等呈较明显的相关性.     

春节期间南京气溶胶质量浓度和化学组成特征

为研究春节期间燃放烟花爆竹对城市大气气溶胶质量浓度和化学组成分布特征的影响,对南京市2012年1月19~31日大气气溶胶质量浓度和水溶性离子及重金属等化学成分进行了观测.结果表明:烟花爆竹的大量集中燃放可使PM1.0的浓度以15.5μg/(m3·h)的速率增长;并使得能见度以1.625km/h的速率急剧下降.质量浓度谱和水溶性离子谱在燃放期均为三峰型分布,在非燃放期为双峰型分布.燃放期PM2.1和PM1.1中的K+、SO42-、NO3-、Cl-和Mg2+所占的比例比非燃放期升高了16%~38%,其他离子浓度变化不大.对于0.2~2.0μm的气溶胶,春节期间硝酸盐、含锌和含铜颗粒主要来自烟花爆竹燃放,含钾颗粒部分来自烟花爆竹燃放,含铅颗粒来自工业排放,烟花爆竹的燃放基本不产生硫酸盐颗粒.     

疏浚对湖泛的影响:以太湖八房港和闾江口水域为例

通过采集太湖八房港和闾江口疏浚后与未疏浚沉积物柱状样于室内模拟“湖泛”的发生与消退过程来研究底泥疏浚对藻源性“湖泛”形成和消退的影响.结果发现,疏浚能有效的延缓“湖泛”发生的时间,八房港和闾江口疏浚后沉积物柱状样水体色度均要低于未疏浚对照样,水体泛黑的时间也分别比未疏浚对照样延迟6d和2d.疏浚沉积物对上覆水柱中营养盐的含量也有较好的控制,试验过程中八房港和闾江口疏浚后沉积物柱状样水体中 NH4+-N的含量仅分别未疏浚对照组的40%和77.1%,PO43--P的含量也仅分别为未疏浚对照组的41.4%和78.1%.值得注意的是,疏浚沉积物所对应的水柱中Fe2+和S2-的含量均要高于未疏浚对照组.八房港和闾江口疏浚沉积物中亚铁的含量分别是未疏浚对照样的78.1%和76.4%,而闾江口疏浚后沉积物中酸挥发性硫化物(AVS)的含量则是未疏浚对照的1.36倍.沉积物中铁、AVS的含量没有表现出明显的垂向分布特征.     

离子强度对粘土和改性粘土絮凝去除水华铜绿微囊藻的影响

研究了水体的离子强度对粘土和壳聚糖改性粘土絮凝去除铜绿微囊藻的影响 .离子强度的增加有利于粘土对藻类的絮凝去除 .与一般粘土除藻相反 ,壳聚糖改性粘土却在离子强度低的条件下具有更好的除藻效果 ,是适合在湖泊 ,水库和江河等淡水 (低含盐量 )水体中应用的应急除藻技术 .当离子强度从 0.17mol/L降到 0mol/L时 ,海泡石除藻率从 90 %以上降为 70 %以下(投加量700mg/L) ,而壳聚糖改性海泡石的除藻率却从 70%左右升至 95% (投加量仅为 11mg/L) .用粘度法研究了壳聚糖改性海泡石的絮凝机理 ,发现相对低的离子强度更有利于壳聚糖分子链上阳电荷的相互排斥作用 ,有利于壳聚糖分子链的舒展 ,从而可以充分发挥架桥网捕作用 ,利于絮凝除藻 .     

Effects of polyaluminium chloride on the freshwater invertebrate Daphnia magna

In a number of countries across the world, aluminium in the form of polyaluminium chloride has been used in the treatment of freshwaters for the direct removal of cyanobacteria, or phosphorus removal, but knowledge about its effect on zooplankton species is poor. In our study, polyaluminium chloride toxicity was tested on both artificial and natural freshwaters for a better understanding and prediction of effects in real ecosystems. Our results indicate that prediction of effects in a real ecosystem based on standard ISO methods is insufficient, and tests with nontarget species (including invertebrates) should be done before each treatment using the water samples from the treated location. Effective concentrations of polyaluminium chloride can differ markedly according to the type of water composition used in the assay. Our experiments proved that EC₅₀ values can fluctuate between 9.89 and 54.29 mg·L^?1 of Al³⁺, and the toxicity is dominantly dependent on the treated water conductivity. This parameter seems to be the dominant source of different effects on zooplankton species after treatment and thus should be properly tested before each use of polyaluminium chloride as a treatment compound.