Prenatal detection of trisomy 21 in uncultured amniocytes by fluorescence in situ hybridization: A prospective study

A prospective study was undertaken to evaluate the use of fluorescence in situ hybridization (FISH) for the detection of trisomy 21 in interphase nuclei of uncultured amniotic fluid cells. Five hundred cases were analysed in situ and classified as normal or abnormal; the results were subsequently checked against the cytogenetic findings. Four hundred and ninety-three were correctly identified as normal with an 86·6 per cent average frequency of scored nuclei exhibiting two signals; six cases were correctly identified as trisomic for chromosome 21 with 81·7 per cent of scored nuclei exhibiting three signals; and one abnormal case involving an unbalanced chromosome 21·21 translocation was falsely scored as normal due to poor hybridization/detection efficiency. The method has been substantially improved and simplified so that it is suitable for the rapid detection of trisomy 21. As aneuploidy detection in interphase does not identify structural chromosome aberrations, it is not a substitute for fetal chromosome analysis.     

长江、嘉陵江(重庆段)源水有机提取物的类雌激素活性评价

为了解长江、嘉陵江(重庆段)源水有机提取物的类雌激素活性，分别于夏季和冬季采用GDX—120大孔树脂对位于城区上、中、下游5个断面长江、嘉陵江(重庆段)源水进行有机物的浓缩提取。用体外MCF—7细胞增殖试验检测有机提取物的类雌激素活性。结果显示，源水有机提取物均具有类雌激素活性。其类雌激素活性中、下游均高于上游，丰水期高于枯水期。     

纳米氧化锌颗粒物通过氧化应激和离子通道失调诱导大鼠气管上皮细胞凋亡的机理

纳米氧化锌具有广泛的工业用途,其生态安全性受到广泛关注,针对纳米氧化锌诱导的呼吸道细胞毒性及其作用机理研究尚不广泛.本研究分别采用不同浓度和粒径(30 nm和90 nm)的氧化锌颗粒物处理大鼠气管上皮细胞(rat tracheal epithelial cells,RTE cells),暴露时间为12 h,通过检测细胞内锌元素含量,细胞增殖抑制率,细胞凋亡率,凋亡相关caspsae 3基因与蛋白相对表达量,细胞内金属硫蛋白活性,ROS和MDA含量、细胞内Ca~(2+)-ATP酶和Na~+/K~+-ATP酶活性来分析纳米氧化锌诱导细胞毒效应机理.在90 nm纳米氧化锌高浓度暴露时,其细胞内锌元素浓度为0.845μg·L~(-1),约为低浓度暴露组的4.7倍,是30 nm低浓度暴露组的9倍;纳米颗粒物诱导的细胞增殖和凋亡毒效应具有剂量和尺寸依赖效应;30 nm处理组的pro-caspase 3和cleaved-caspase 3蛋白表达量均高于90 nm暴露组;暴露浓度为10 mg·L~(-1)的90 nm处理组的金属硫蛋白增加量为0.533μg·L~(-1),增幅达到46%;不同粒径氧化锌颗粒物处理后,细胞内ROS和MDA含量显著上升,且30 nm处理组结果均高于90 nm处理组;纳米氧化锌颗粒物暴露诱导细胞Ca~(2+)-ATP酶和Na~+/K~+-ATP酶活性显著下降,30 nm氧化锌颗粒物暴露组,其Na~+/K~+-ATP酶活性分别是对照组的1.8倍和3.5倍.纳米氧化锌颗粒物进入RTE细胞,通过干扰锌在细胞内代谢,诱导细胞内ROS和MDA水平升高,产生氧化应激,进而诱导细胞凋亡是导致纳米氧化锌产生细胞毒性的主要原因之一.纳米氧化锌会导致细胞内Ca~(2+)-ATPase和Na~+/K~+-ATPase活性下降,离子通道失调,破坏细胞内离子平衡,进一步造成细胞凋亡.     

Fe2+和零价铁活化过一硫酸盐降解酸性橙7

采用环境友好的Fe~(2+)和零价铁(ZVI)作活化剂,活化过一硫酸盐(PMS)来降解水中酸性橙7(AO7).结果表明,在Fe~(2+)-PMS体系中,AO7的降解效果不佳,但通过添加适量的络合剂,AO7的去除率会大幅提高.ZVI在PMS存在下被腐蚀,并能够缓慢、持续不断地释放Fe~(2+).ZVI-PMS体系可以在比较宽泛的pH范围(3～9)有效、快速地降解AO7,并且在酸性条件下降解速率较快.淬灭实验结果显示,硫酸根自由基(SO_4~(·-))对AO7的降解起主要作用.除了Cl~-和高浓度(50 mmol·L~(-1))的NO_3~-能够促进AO7的降解外,其他水中共存的阴离子对AO7在ZVI-PMS体系中的降解具有抑制作用,而腐殖酸(HA)则无明显影响.AO7在超纯水中的去除率高于其他实际水体,但反应90 min后,污水厂出水过滤水和胶体浓缩液中的AO7去除率也可高达98.6%和87.6%,说明ZVI-PMS可能可以有效地去除含有较高DOC含量的污水中的AO7.利用GC-MS检测到辐照后溶液中有3种中间产物,推测主要是通过AO7偶氮键断键后的中间产物进一步氧化形成.此外,TOC在一定程度上降低,说明部分AO7被矿化.     

Co(Ⅱ)活化过氧乙酸降解有机染料研究

采用Co(Ⅱ)活化过氧乙酸(PAA)降解有机染料,主要评估了Co(Ⅱ)/PAA体系的氧化性能并考察不同因素对酸性橙(AO7)脱色的影响.结果表明:Co(Ⅱ)/PAA体系能有效脱色有机染料,其氧化能力与Co(Ⅱ)/PMS体系相当并优于Fenton体系. AO7的脱色效果随PAA和Co(Ⅱ)浓度的升高而升高,其中,[Co(Ⅱ)]_0为0.01 mmol·L~(-1)、[PAA]_0/[AO7]_0为4/1时,反应60 min可使92%的AO7脱色.弱酸或中性的环境有利于AO7的脱色,存在Cl-和HA时不利于AO7的脱色.采用抑制剂抗坏血酸、叔丁醇、甲醇等实验方法,推测Co(Ⅱ)/PAA体系中产生的CH_3COO·和CH_3COOO·是对AO7起主要降解作用的自由基.紫外可见光谱分析表明,该自由基主要攻击AO7分子中的偶氮键及萘环结构,从而达到AO7脱色效果.     

7B04铝合金海洋性大气腐蚀研究

通过在青岛和海南开展的7B04铝合金户外大气暴露试验,利用失重分析、形貌观察、断面分析和电化学交流阻抗谱等研究了7B04铝合金在海洋性大气环境中的腐蚀动力学规律和腐蚀特征。结果表明,在青岛和海南等海洋性大气环境中,7B04铝合金腐蚀初期以点蚀形式萌生,随后向均匀腐蚀发展;腐蚀过程均经历了腐蚀速率由高到低的过程,且腐蚀失重与时间的关系均可用幂函数显著回归;电化学阻抗谱分析表明当腐蚀产物足够厚时,7B04铝合金海洋性大气腐蚀的电化学过程由侵蚀性离子的扩散步骤来控制。     

Mechanism of Deca-BDE-induced apoptosis in Neuro-2a cells: Role of death-receptor pathway and reactive oxygen species-mediated mitochondrial pathway

Decabromodiphenyl ether (BDE-209) is a prevalent polybrominated diphenyl ether (PBDE) congener known to have neurotoxicity. Effects of BDE-209 on Neuro-2a cells were performed in the present study and the possible apoptotic pathway was discussed. Results indicated that BDE-209 induced Neuro-2a cell apoptosis, increased the protein expression of Fas and Fas-associated death domain-containing protein (FADD) and activated the caspase-8 and -3 activities in a concentration-dependent manner, inferring the death-receptor pathway was involved in the apoptotic process. Meanwhile, BDE-209 exposure increased the Bax/Bcl-2 ratio and decreased the cellular mitochondrial membrane potential (MMP) which led to cytochrome C released to the cytoplasm. The intracellular caspase-9 was elevated simultaneously, which caused downstream caspase cascade and triggered cell apoptosis. Moreover, BDE-209 exposure increased cellular reactive oxygen species (ROS) level in a concentration-dependent manner and the addition of N-acetyl-l-cysteine (NAC), known as ROS scavengers, obviously reduced the apoptotic rate and a positive relationship was observed between the degree of apoptosis blocking and the loss of MMP and ROS production. We thus concluded that BDE-209 induced Neuro-2a cell apoptosis via the combination of the death-receptor signaling pathway and the mitochondrial signaling pathway. The elevated ROS production was considered to magnify the intracellular apoptosis signal and played a crucial role in apoptosis of Neuro-2a cells induced by BDE-209.     

7A52铝合金干湿交替情况下电偶腐蚀行为研究

目的研究海洋环境下7A52铝合金在干湿周浸使用过程中的电偶腐蚀现象。方法实验配制3.5%的Na Cl水溶液浸泡试样,实验周期为504 h,全浸试样作为对比试样,在实验周期内一直浸泡在Na Cl水溶液中。测试试样干湿周浸情况下7A52与5A06,38Cr Si之间的电偶电流及电偶电压,使用SEM分析腐蚀后的表面形貌。结果 7A52-5A06干湿周浸试样电偶电流变化不大,全浸试样电偶电流较初期变化较大,后期电偶电流的大小只有初期电偶电流大小的1/8左右,7A52-38Cr Si全浸试样与干湿交替情况下电偶电流基本相同。随着试验的进行,干湿交替及全浸情况下电偶电流的差异逐渐变大,电偶电流增大约为实验初期的10倍;全浸情况下试样表面腐蚀产物较致密,干湿周浸情况下腐蚀产物较为疏松。结论在3.5%的Na Cl水溶液干湿周浸情况下,7A52-5A06,7A52-38Cr Si的平均电偶腐蚀速度要大于全浸状态下的平均电偶腐蚀速度,干湿周浸情况下,7A52-5A06,7A52-38Cr Si腐蚀后试样表面形态具有较大差异,5A06在相同实验条件下的耐腐蚀性要好于7A52。     

7-ACA清洁生产的潜力研究

7-ACA是头孢菌素关键性中间体。近年来,头袍菌素类抗生素使用越来越多,临床应用证明它是一类抗菌谱广、抗菌活性强,疗效高和毒性低的抗生素。然而,中国在7-ACA生产过程中普遍面临着污染重、废弃物成分复杂、治理难度大的发展"瓶颈"。本文从清洁生产源头消减的角度,分析了7-ACA清洁生产的潜力与机会,并在国内7-ACA生产现状下,提出了化学法清洁生产方案的建议。     

BPA暴露对本体和子代胰岛β细胞转录组差异对比分析

双酚A(BPA)作为一种典型的环境内分泌干扰物,与二型糖尿病和肥胖症等代谢类疾病密切相关.在这项研究中,旨在探讨BPA直接暴露以及围产期暴露对本体和子代胰岛β细胞影响的差异,从而实现对不同易感人群的精准预防与治疗.通过对GEO数据库中GSE126297和GSE82175两个数据集进行分析,共筛选出108个共有的差异基因,其中28个表达趋势一致,而另外80个表达趋势相反.随后对本体和子代单独的差异基因,以及共有差异基因进行了GO和KEGG对比分析.此外,利用String数据库和Cytoscape分析PPI网络中的紧密联系的基因,并将其可视化,进一步从28个表达趋势一致的基因中筛选出相互作用最为紧密的基因集1(Iqgap2,Igf2r和Rab18);从80个表达趋势相反的基因中筛选出相互作用紧密的基因集2(Polr2f,Ccnt2,Polr2e,Kdm7a,Fbl)和基因集3(Atp5g2,Atp5o和Ndufa6).最后,通过GEPIA在线验证上述基因在胰腺癌样本中的表达,研究发现Rab18,Polr2f,Polr2e,Fbl,Atp5g2,Atp5o和Ndufa6在胰腺癌病例中的表达均显著上升.同时,上述基因在本体中呈现显著上升趋势,而对于子代,只有Rab18显著上升,其他基因则呈下降趋势.综上,BPA对本体和子代的影响有一定的关联,其中关联的关键基因的异常表达可能会增加本体罹患胰腺癌的风险,而对于子代则会影响代谢过程和细胞结构.