Cytogenetic prenatal diagnosis and its relative effectiveness in the mersey region and North Wales

The relative effectiveness of cytogenetic prenatal diagnosis in the Mersey Region and North Wales is presented by estimating the percentage detection rates of Down's syndrome annually following amniocentesis from 1978–1984 inclusive. Tables indicating the percentage of screened pregnancies, types of chromosomal aberrations detected and the occurrence of Down's syndrome in mothers in age groups of five-year intervals are also presented. The average prenatal detection rate for Down's syndrome (estimated at the time of birth) was 15–15 per cent over the years 1978–1984 and was above 22 per cent for the last two years when 44–13 per cent of all pregnancies to mothers of 35 years and over were investigated.     

磁处理水的处理作用及其影响分析

通过磁场在工业废水、城市污水和饮用水处理中的应用，对磁场处理水的物理作用原理及其影响因素进行了分析。指出了磁场在水处理中的应用优势和磁场效应与各种水处理技术共同作用实现多种水处理功能的技术前景。     

高技术产业污染

通过对美、日两国高技术产业污染现状的分析，得出了高技术生产并非清洁的结论，分析了我国高技术污染的现状和其潜在的危害，提出了防止高技术污染的措施。     

Prenatal diagnosis of 49,XXXYY

The first prenatally diagnosed case of 49,XXXYY is reported. The pathological findings of the fetus included bilateral clinodactyly, decreased carrying angles (OO), and hypertelorism, slightly low set ears and mildly prominent forehead. A minimum of two independent non- disjunctional events are postulated for this polysomy to arise.     

Possible effect of gestational age on the detection of fetal nucleated erythrocytes in maternal blood

Maternal venous blood samples, obtained from six pregnant women, were used as a source of fetal nucleated erythrocytes (NRBC). Fetal cell enrichment was potentiated by flow sorting with the monoclonal antibodies Tf R, Leu-4, and Leu-M3. Single copy Y chromosomal DNA sequences were detected in samples obtained from two women at 11 and 12 weeks' gestation. Y DNA sequences were absent in a subsequent sample from one of these women at 19 weeks and in two other women at 16 and 20 weeks. All four women delivered males. Y DNA sequences were not detected in two women who delivered females. By combining these results with prior data on the detection of Y chromosomal DNA sequences in maternal blood from male-bearing pregnancies, a relationship between gestational age and feta-maternal transfer of NRBC is suggested.     

发展循环经济是解决环境污染的根本途径

要解决我国的环境污染问题,必须应用循环经济原理,合理规划工业布局,优化原有工业企业分布,形成社会、企业之间、企业内部的废弃物品、余热、余能、废弃物质循环利用,从源头上控制污染物的产生,才是解决环境污染的根本途径.     

Characterization of i(18p) in prenatal diagnosis by fluorescence in situ hybridization

A case is presented in which chorionic villus direct preparation and cultured chorionic villus cells revealed a 47,XX, + mar karyotype. The marker was a small metacentric chromosome and appeared to be i(18p)—isochromosome 18p. Follow-up studies in both amniotic fluid and fetal fibroblasts confirmed the karyotype. In order to characterize the marker, a panel of biotinylated DNA probes was used, including a whole chromosome 18 probe, chromosome 18-specific alpha satellite DNA, Yac clones, and a pan-telomeric probe. These studies show that the marker is a monocentric i(18p) in which about 80 per cent of chromosome 18 alpha satellite DNA has been lost.     

Inv dup (15): Prenatal diagnosis and postnatal follow-up

A de novo inv dup (15) was diagnosed at amniocentesis. No physical abnormalities were detected after birth. The boy developed severe mental and motor retardation, which became obvious at 16 months of age.     

A fetus with a chromosome 13 ring and placenta with chromosome 13 rod/ring mosaicism

A fetus was identified by prenatal cytogenetic diagnosis as having a karyotype 46,XY,r(13) (p11q13). Termination of the pregnancy yielded a severely malformed fetus. Fetal abnormalities included anencephaly, imperforate anus and urethral meatus, severe talipes, syndactyly, cardiac defects and other anomalies. Confirmatory studies on cultured placental villi cells indicated a second cell line, 46,XY, −13,+ 13qter→cen::13ql3→qter. This cell line was not detectable in cells derived from the fetus despite extensive studies. It seems likely that the two cell lines arose simultaneously with selection favouring the 46,XY,r(13) line. How the chromosome rearrangements may have arisen is discussed. We are unaware of other cases where a cell line identifiable by a chromosome abnormality appeared to be confined to placental tissue. However, studies on placental tissue may be helpful in understanding the origin of other unbalanced de novo rearrangements.     

石崆山Ⅱ号段岩质高边坡稳定性的有限单元法(FEM)分析评价

岩质高边坡是常见的自然地质环境问题和重要的岩土工程问题之一,涉及工程地质学、岩体力学问题。针对漳州—龙岩高速公路石崆Ⅱ号段岩质高边坡稳定性问题,采用有限单元法(FEM)进行计算分析。计算分析结果表明石崆山Ⅱ号段岩质高边坡是稳定安全的。有限单元法在岩质高边坡稳定性的计算分析中的应用,正处在完善和发展之中。它的计算分析正确与否或精确程度,很大程度上取决于对边坡岩体工程地质条件的正确理解和归纳概化,取决于计算参数的合理客观选取。