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1.
本文对大连近海海域15个表层沉积物样品中16种多环芳烃(PAHs)污染特征及来源进行研究。结果表明,沉积物中16PAHs总浓度为30.0410-9~89.2410-9,平均值为50.8410-9,其中工业区显著高于城市地区(p0.05),极显著高于农村地区(p0.01)。沉积物中PAHs含量与总有机碳(TOC)含量间存在显著正相关性(p0.05),表明沉积物有机质含量是影响PAHs含量的主要因素。主成分分析得出,大连近海海域PAHs污染源为石油泄漏造成的石油源、生物质及化石燃料燃烧形成的燃烧源和燃油燃烧形成的交通源。  相似文献   

2.
Investigation of a couple, who had produced three babies with cri du chat syndrome, showed initially that the mother had an apparent deletion of chromosome 5. It seemed likely that she had a balanced chromosomal translocation but it proved impossible to detect the second chromosome involved using routine cytogenetic methods. Molecular techniques using quantitative hybridization dosage studies were performed and these showed that the mother had a double dose of DNA in the suspected delected area of chromosome 5. Further studies, using in situ hybridization techniques, revealed that the missing segment of chromosome 5 had translocated onto the short arms of a C group chromosome and further analysis of prometaphase chromosomes showed the presence of a balanced translocation, 46,XY, t(5;9)(5qter → 5p14.1::9p22 → 9pter;9qter → p22::5p14.1 5pter). As a result of these findings, it was possible to offer prenatal diagnosis to the patient in furture pregnancies, by detecting the presence of a balanced or unbalanced translocation in the fetus using molecular and cytogenetic techniques.  相似文献   

3.
渤海表层沉积物中多环芳烃赋存特征及来源分析   总被引:4,自引:2,他引:2  
对渤海表层沉积物中典型持久性有毒物质多环芳烃的浓度水平、空间分布及污染来源进行了探讨,结果表明,PAHs总量(PAHs)的浓度范围为(21.9~ 586.4)10-9(干重,dw),平均值为175.110-9 dw,其中渤海湾海区PAHs的整体含量要明显高于其它区域,平均含量达到430.910-9 dw。PAHs与总有机碳(TOC)含量二者之间呈显著线性相关(p0.05),表明有机质含量是影响PAHs在海水中迁移和分配的一个主要因素。不同环数PAHs的特征分布表明,渤海海域PAHs主要来自石油及其产品、煤和生物质的燃烧。  相似文献   

4.
We present a case in which amniocentesis performed at 33 weeks' gestation because of symmetrical intrauterine growth retardation and decreased amniotic fluid volume led to the prenatal diagnosis of a fetus with a karyotype of 47,XX,+9, t(1;20)(q42;p11.2) pat, i.e., with an extra chromosome 9 and a balanced translocation between chromosomes 1 and 20. At delivery, the baby showed clinical features of trisomy 9, yet chromosome analysis of the cord blood revealed no trisomy 9 cells, a finding confirmed by neonatal blood karyotyping. The balanced translocation was present in all cells. A skin biopsy confirmed trisomy 9 mosaicism with 10 per cent trisomy 9 cells. The baby died at 6 weeks and an autopsy was obtained. Chromosome analysis of different organs demonstrated different frequencies of the mosaicism of trisomy 9. The possible underlying mechanism for the discrepancy between the karyotype results by amniocentesis and those of other tissues is discussed.  相似文献   

5.
An extra small chromosome detected in amniotic fluid was identified as the product of a translocation [46,XX,t(9;15)(p24;q11.2)]. This case is unusual in that individuals with the unbalanced karyotype resulting from a 3:1 disjunction are phenotypically normal.  相似文献   

6.
The detection of very rare variants in prenatal diagnosis often causes counseling difficulties and anxiety in parents. We describe a duplication of the proximal region of chromosome 9 short arm in two cases of prenatal diagnosis and in one young woman, with evidence that such rearrangement is an uncommon variant. The duplication was investigated using Fluorescence in situ hybridization (FISH). Although the cytogenetic findings were indicative of a ‘duplication 9p syndrome’ associated with mental and developmental retardation, we were able to demonstrate that the rearrangement was a heteromorphism with no phenotypic consequence. We also determined the breakpoint regions of the rearrangement and identified the BAC probes that precisely define the duplicated region devoid of risk of phenotypic effects. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

7.
Two cases of amniotic fluid cell cultures are reported, where a familial, non-heterochromatic 9p+ variant has been found.  相似文献   

8.
We present a case of a twin with trisomy 47,XX+i(9p) in whom the diagnosis of cleft palate was confirmed by colour Doppler imaging demonstrating abnormal fluid flow across the fetal pharyngeal bone defect. Application of this technique in cases predisposed for this congenital lesion may prove beneficial in the diagnosis of the more subtle types of isolated cleft palate.  相似文献   

9.
采用快速溶剂萃取法提取土壤中的7组多氯联苯Aroclors系列,经弗罗里硅土柱净化,用气相色谱/电子捕获检测器法(GC/ECD)和气质联用法(GC/MS)进行测定。当取样量为20g时。GC/ECD法和GC/MS法的检出限分别为0.28~0.87μg/kg和0.62~1.35μg/kg。两种方法的基体加标回收率在79.6%--103.6%,相对标准偏差〈9.0%。利用该方法分析Aroclor有证土壤标样,结果满意。GC/ECD法的准确度和精密度略优于GC/MS法,因此实际土壤样品Aroclors分析中,建议以GC/ECD的定量结果为准。  相似文献   

10.
Extra genetic material that is euchromatic is generally regarded to be associated with phenotypic abnormalities. However, recent studies suggest that this is not always the case. Chromosome analysis was performed on amniotic fluid cells from a 37-year-old phenotypi-cally normal patient referred for advanced maternal age. All the cells analysed showed a karyotype of 46, XY, 1p-K The 1p+ chromosome had extra genetic material of uncertain origin in chromosome band region 1p21 →31. Chromosome analysis on the father revealed a normal 46, XY male karyotype. The mother's karyotype showed the same 1p+ chromosome. C and Q banding, as well as silver staining studies, in both the mother and the fetus support the interpretation that the extra chromosomal material was euchromatic in nature. This 1p + chromosome may be characterized as a euchromatic heteromorphism. Euchromatic hetero-morphisms not associated with phenotypic abnormalities have been reported for chromosomes 9 and 16. To the best of our knowledge, this is the first report involving this type of cytogenetic anomaly on chromosome number 1 in a phenotypically normal mother and infant.  相似文献   

11.
12.
We describe three cases in which we used fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) and comparative genomic hybridization (CGH) to characterize Y chromosome structural anomalies, unidentifiable by conventional G-banding. Case 1 was a 46,X,+mar karyotype; FISH analysis revealed an entire marker chromosome highlighted after hybridization with the Y chromosome painting probe. The PCR study showed the presence of Y chromosome markers AMG and SY620 and the absence of SY143, SY254 and SY147. CGH results confirmed the loss of Yq11.2-qter. These results indicated the presence of a deletion: del(Y)(q11.2). Case 2 was a 45,X [14]/46,XY[86] karyotype with a very small Y chromosome. The PCR study showed the presence of Y chromosome markers SY620 and AMG, and the absence of SY143, SY254 and SY147. CGH results showed gain of Yq11.2-pter and loss of Yq11.2-q12. These results show the presence of a Yp isodicentric: idic(Y)(q11.2). Case 3 was a 45,X,inv(9)(p11q12)[30]/46,X,idic(Y)(p11.3?),inv(9)(p11q12)[70] karyotype. The FISH signal covered all the abnormal Y chromosome using a Y chromosome paint. The PCR study showed the presence of Y chromosome markers AMG, SY620, SY143, SY254 and SY147. CGH only showed gain of Yq11.2-qter. These results support the presence of an unbalanced (Y;Y) translocation. Our results show that the combined use of molecular and classical cytogenetic methods in clinical diagnosis may allow a better delineation of the chromosome regions implicated in specific clinical disorders. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

13.
Three different types of chromosome 12 inversion were seen in 15 individuals out of 44 individuals examined in one 8 generation family. Type 1: a pericentric inversion inv(12) (p112; q131) was found in 7 individuals and twice at prenatal diagnosis. Type 2: a paracentric inversion inv(12) (p123; p131) was seen in two individuals. Two individuals carried both inversion chromosomes, namely type 1 and type 2. The two inversion chromosomes were transmitted from each of the parents. Type 3: a double pericentric and paracentric inversion (type 3) inv(12) (p123; p131) (p112; q131) was observed in the daughter of one of the carriers of type 1 and 2 inversions and again at prenatal diagnosis in her son. The double inversion most likely arose through crossing-over in between the two inversion loops. A balanced translocation t(7; 13) and the inversion type 1 was observed in one individual, who transmitted the translocation only to an offspring. The frequency of inversions in amniotic fluid cells observed in our laboratory was 1·9 per cent. The clinical implications of these findings are discussed.  相似文献   

14.
江苏沿海化工区环境风险分级及优先管理策略研究   总被引:3,自引:0,他引:3       下载免费PDF全文
以江苏沿海40家化工园区为例,综合考虑化工园区评价单元与环境风险区域性、系统性和行业性特征,构建了包括风险源、控制机制、风险受体3项一级指标、9项二级指标的环境风险分级综合模型,提出以指标贡献率作为优先管理策略的半定量筛选依据.结果表明,研究区域内共有江苏响水陈家港化工集中区、江苏连云港化工产业园区、如皋精细化学工业园等7个高风险园区,其风险产生与园区产业结构、园区地理布局紧密相关.根据指标贡献度将7个高风险化工园区划分为两类化工园区:一类是以受体敏感性为主控风险因素的化工园区;一类以风险源以及风险控制为主控因素的化工园区.针对这两类化工园区,分别从环境监管、提高清洁生产水平、化工企业数量总量控制、污水处理厂及配套管网建设等方面提出优先管理策略.  相似文献   

15.
提出能计算平均年和典型年生态基流量的基于CAWDU(建设项目水资源论证导则)的代表年法(简称IGAWDU法),建立了相应的公式,应用于滦河中游典型河段。通过天然径流量趋势分析,确定自然与人为干扰的转折点,选取用于生态基流量计算的数据。采用双因素方差分析法比较逆月最小生态径流法(M—MMER法)和IGAWDU法与Tennant法的差异度。结果表明:(1)基于IGAWDU法的多年平均生态基流量为1.412亿m^3,丰、平、枯水年的年生态基流量分别为2.977亿m^3,1.736亿m^3,0.834亿m^3,占年均天然径流量32.4%,18.9%,9.1%,丰、平水年可满足维持生态系统所需基本水量;(2)M—MMER法与Tennant法的差异性较大。基于GAWDU的平均年法与Tennant法差异性不显著;(3)基于IGAWDU法的生态基流量略高于Tennant法,更利于河道生态系统健康发展,适于滦河流域生态基流量的估算。  相似文献   

16.
An Erratum has been published for this article in Prenatal Diagnosis 23(9) 2003, 771 Antenatal detection of an isolated abdominal cyst was found to be a pancreatoblastoma in a female fetus with Beckwith–Wiedemann syndrome. Prenatal and post-natal features and management of this very rare tumour are discussed. Molecular investigation disclosed a mosaic paternal 11p15 uniparental disomy in the tumoral cells. The prognosis of a congenital pancreatoblastoma is good if complete surgical excision is achieved. However, the association with Beckwith–Wiedemann syndrome requires a prolonged follow-up because of the increased risk of developing malignant tumours. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

17.
Effect of chromium on growth attributes in sunflower (Helianthus annuus L.)   总被引:2,自引:0,他引:2  
Heavy metal soil pollution takes place when the metal concentration of soil exceeds natural background level and causes ecological destruction and deterioration of the environment.In the present study,a pot experiment was conducted to evaluate the effect of chromium-contaminated soil in sunflower(Helianthus annuus L.)growth attributes.Three different levels of chromium(Cr)i.e.,20, 40,and 60 mg/kg were applied to three varieties of sunflower(G-3,G-9,and G-59).The results of morphological,chemical,and yield p...  相似文献   

18.
生态NMHC对臭氧和PAN影响的数值模拟研究   总被引:10,自引:0,他引:10       下载免费PDF全文
利用数值模拟方法结合GEIA生态源排放清单,研究了夏季我国东部生态系统排放非甲烷烃(NMHC)对臭氧和过氧乙酰硝酸脂(PAN)的影响,阐明了生态NMHC在大气化学系统中的重要作用。研究结果表明,生态NMHC使我国东部大部分地区臭氧和PAN增加,最大平均增量分别为9ppb和0.6ppb;白天最大平均增量分别达到21ppb和1.2ppb,最大增量地区位于长江三角洲的浙江、上海附近地区。模拟结果与实测值有好的一致性,研究结果表明对于区域和城市臭氧的模拟及其控制应该充分考虑生态源的作用。  相似文献   

19.
The effect of pre-treatment of dewatered sludge using different nitrite concentrations and pH for microbial fuel cell (MFC) application was investigated. The results show that the addition of nitrite was feasible to increase the solubilization rate of the sludge and may reduce mass transfer limitation at the anode. This helped the MFC to reach higher voltage and to generate more power. The higher free nitrous acid (FNA) concentration under the acidic condition helped to increase sludge solubilization. However, under an alkaline condition, during which the FNA concentration was relatively low, the solubilization of the sludge was higher. The highest voltage and power density produced was 390?mV and 153?mW/m2, respectively, with the addition of nitrite at 100?mg-N/L and pH?9. Furthermore, it was found that elevated levels of FNA could inhibit electrogenic bacteria thus reducing power generation.  相似文献   

20.
南京北郊工业乡村混合区秋季边界层VOCs垂直分布特征   总被引:1,自引:0,他引:1  
利用2020年秋季南京北郊低对流层(0~1 000 m)VOCs探空实验数据,分析了该地区VOCs垂直廓线分布及其日变化、光化学反应性等特征.结果表明,φ(VOCs)随高度升高而降低(72.1×10-9±28.1×10-9~56.4×10-9±24.8×10-9).各高度上烷烃占比最大(68%~75%),其次为芳香烃(10%~12%)、卤代烃(10%~11%)、烯烃(3%~7%)和乙炔(2%).边界层日变化对VOCs廓线影响较大,早晚较低的边界层致使VOCs在近地面累积,而在上部体积分数较低;午后VOCs的垂直分布则较均匀.上午光化学反应性强(弱)的烯烃(烷烃)等的体积分数占比随高度升高而减小(增加),说明高层的VOCs光化学老化显著.午后VOCs各组分占比及其OFP在低对流层内垂直分布则较均匀.受周边不同来源气团影响,各高度φ(VOCs)及组分占比差异明显,工业气团在200~400 m;高度间φ(VOCs)随高度升高,芳香烃占比增大;城区气团φ(VOCs)垂直负梯度最大,近地面φ(VOCs)较高,...  相似文献   

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