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161.
The detailed study of the fetal cardiac anatomy in the first trimester of pregnancy by means of ultrasound, transvaginally or transabdominally, is feasible and remains a safe procedure provided thermal and mechanical indices are taken into account. Optimal time for successful imaging of the four chambers and great arteries in early gestation appears to be between 13 to 14 weeks. In experienced hands, first-trimester fetal echocardiography is accurate in detecting major structural cardiac abnormalities and yields a high negative predictive value. Thus, in a clinical setting, it can be offered to families considered to be ‘at risk’ of cardiac defects (e.g. those with previous family history or when fetal nuchal translucency is increased) and can be a powerful tool to reassure families regarding normality of major cardiac structures and connections. However, the early detection of an important structural abnormality (chromosomally normal or not) may be associated with a high termination rate if this is an acceptable option. The high prevalence of associated chromosomal and extracardiac abnormalities for many of the high-risk families, who may benefit from this approach, cannot be ignored. Therefore, fetal heart scanning in the first trimester should be performed in conjunction with detailed first-trimester obstetric scanning. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
162.
163.
Sialic acid storage disorders, Salla disease (SD) and a severe infantile form of disease (ISSD), are recessively inherited allelic lysosomal storage disorders due to impaired egress of free sialic acid from lysosomes. Fourteen pregnancies at risk of adult-type free sialic acid storage disease, SD, were monitored by sialic acid assays, genetic linkage or mutation detection analyses using chorionic villus samples. Three affected and 12 unaffected fetuses were identified. The first studies were based on the sialic acid assays alone, but the location of the gene enabled the use of genetic linkage analysis and, more recently, the identification of the SLC17A5 gene and disease-causing mutations added yet another possibility for prenatal studies. A missense mutation 115C→T (R39C) is present in 95% of all Finnish SD alleles, providing an easy and reliable means of diagnostic studies. Both molecular and biochemical (sialic acid assay) studies can be used for prenatal diagnosis of free sialic acid storage diseases. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
164.
A prenatal diagnosis of Pelizaeus-Merzbacher disease (PMD) resulting from proteolipid protein gene (PLP) duplication was performed by a quantitative fluorescent multiplex PCR method. PLP gene copy number was determined in the proband, the pregnant mother, the male fetus and two aunts. Small amounts of genomic DNA extracted from peripheral blood and from chorionic villi were used. The fetus, in common with the proband, was identified as PMD-affected being a carrier of the PLP gene duplication, inherited from the mother, while the two aunts were non-carriers. The data obtained were confirmed by segregation analysis of a PLP-associated dinucleotide-repeat polymorphism amplified by the same multiplex PCR. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
165.
It has been nearly 20 years since a working definition for “sustainable development” was put forward by the World Commission on Environment and Development. The concept endures in the mission statements and frameworks of action of various societal actors, including those of neighborhood associations, metropolitan development authorities, environmental ministries, and United Nations (UN) specialized organizations, to name a few. Yet many observers doubt that sustainable development is occurring in poor countries. This failure, the critics contend, stems from miserly transfers of foreign aid. The extent to which inadequate aid is to blame for poor environmental/developmental outcomes is an open question. But vocal demands for increasing aid to meet sustainable development goals come from many parts of society and are persistent. Exhortations for more aid to help poor countries are noble, perhaps even justifiable, but there are understandable doubts about the wisdom of transferring large capital and technical resources to countries that are slow to adopt needed institutional reforms. Aid without institutional reform is a recipe for wasted resources and donor fatigue. Worse, it may enhance inequities of wealth and power in recipient countries. There are few illustrations to draw on demonstrating how institutionally impoverished societies are affected when they are compelled to absorb massive aid inputs over a short period––a remedy suggested by some prominent aid experts. As a proxy, it is valuable to examine instances where swift macroeconomic changes, spurred by external investment and export-led growth, has occurred without significant institutional development. The case of Equatorial Guinea and its sudden oil riches is examined to discern whether, in the absence of meaningful institutional reform, rapid and profound increases in foreign direct investment and export income enable poverty alleviation and sustainable development.
Matthew R. AuerEmail:
  相似文献   
166.
大气污染对呼吸系统疾病的影响——以河南省A市为例   总被引:1,自引:0,他引:1  
文章将二氧化硫(SO2)、二氧化氮(NO2)、可吸入颗粒物(PM10)等主要污染物的监测浓度值与呼吸系统疾病(支气管炎、肺炎、哮喘)住院人数进行相关性分析,以探讨A市大气污染对呼吸系统疾病的影响。研究结果表明,二氧化氮(NO2)和可吸入颗粒物(PM10)对支气管炎住院人数有显著影响,可吸入颗粒物(PM10)还与哮喘住院人数有密切的关系,因此A市大气污染可能与呼吸系统疾病的环境病因有关。  相似文献   
167.
大骨节病是一种骨关节变形地方性慢性病。该病病因复杂,以生物地球化学和地球化学生态学理论为指导,在研究区进行水文地质环境调查,并对饮水水样分析对比,发现病区饮水水源低矿化度、高腐殖酸是大骨节病患病的重要因素,据此在病区开展改水工程,探讨利用深层地下水改善病区饮水水质和提高居民生活水平的有效性,为大骨节病致病水源假说提供相关的理论依据,同时为病区综合防治大骨节病提供相关经验。  相似文献   
168.
George Lakoff 's work in cognitive linguistics has prompted a surge in social scientists’ interest in the cognitive and neuropsychological dimensions of political discourse. Bringing cognitive neuroscience into the study of social movements and of environmental communication, however, is not as straightforward as Lakoff 's followers suggest. Examining and comparing Lakoff's “neuropolitics” with those of political theorist William E. Connolly, this article argues that Connolly's writings on evangelical-capitalist and eco-egalitarian “resonance machines” provide a broader model for thinking about the relations between body, brain, and culture. Environmentalists, it concludes, should pluralize their “frames” and pay greater attention to the micropolitical and affective effects of their language and practices on the communities within which they act, communicate, and dwell.  相似文献   
169.
Since the early 1960s, many investigators have reported that blackfoot disease, a peripheral vascular disease, observed in southwestern Taiwan is due to drinking the higher arsenic concentration in well water. However, recent studies indicated that the relationship with blackfoot disease is not only with arsenic but also humic substances. This paper presents some results concerning the characterization (such as fluorescence, elemental composition, molecular weight and carbon distribution) of humic substances isolated from the Fuhsing well water of the blackfoot disease area. For comparison, the dissolved organic carbon (DOC) and humic substances in the normal well water from Chiuying and the Nanwan coastal water were also analyzed. In general, in the well water of the blackfoot disease area, extremely high concentrations of DOC (18.5mg/L) and fulvic acid (7.54mg/L) with high fluorescence intensity (59.1, equivalent to 0.0282uM quinine sulfate solution) and high percentages (over 50%) of low molecular weights of less than 1,000 were obtained compared with those of normal waters. C‐13 Nuclear magnetic resonance spectroscopy showed a high content (37.2%) of aromatic carbon. These higher concentrations of DOC and fulvic acid with the higher content of aromatic carbon in well water might be one of the key factors causing the blackfoot disease in Taiwan.  相似文献   
170.
分析了阿坝地区的岩石、饮用水、农作物及其根系土中硒的不同存在形态的分布,并结合生物有效性深入研究了硒元素分布与大骨节病病因的联系和调控机理.阿坝地区的环境(岩石、土壤、水)中全硒浓度、农作物中硒的富集系数和水溶性硒占总硒的含量均远低于非病区;硒在氧化还原条件(Eh平均值143.27 mV)和酸碱度(pH 6.51—8.48)的控制下主要以亚硒酸态的稳定形式存在.元素铝、铁等的富集可能会促进硒的沉淀和络合,制约硒的生物有效利用率,进而导致人体硒摄入不足,最终激发人类微小病毒B19(HPV B19)的毒性,引发大骨节病.通过采取土壤增施硒肥、改善水质、改变膳食结构等方法可以有效地提高环境中硒的水平及其生物有效性,以缓解大骨节病的病情及发病率.  相似文献   
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