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971.
在充分吸收和消化活动断裂、活动盆地、地球物理场、地震活动、现代构造应力场和地震前兆资料的基础上,归纳总结出它们与地震活动的关系,确定了地震活动的时、空、强判定标志和原则,综合判定了中期(3~5年)和中短期(1~3年)地震危险区,为地震的短临监测预报跟踪提供了依据。  相似文献   
972.
沥青烟中苯并(a)芘的等速采样与监测   总被引:3,自引:0,他引:3  
新的大气污染综合排放标准对沥青及碳素制品生产和加工制定了标准,然而空气和废气监测分析,方法没有给出沥青烟气中苯并(a)芘的分析方法,该文用气相色固定谱固定液滤筒等速采样,进行沥青烟苯并(a)芘的分析,及其设计的气态衍生物富集器,为执行新的大气污染物综合排放标准提供了可行的技术保证。  相似文献   
973.
活性污泥法快速培菌的探索与实践   总被引:2,自引:0,他引:2  
本文介绍了一种快速培养,驯化活性微生物的方法,大大缩短了微物生长的停滞期,使活性污泥在培菌、驯化方面有很大的改进,做到节约时间、降低成本、减轻培菌期间的环境污染。使活性污泥法更加快速、高效。  相似文献   
974.
Serum human chorionic gonadotrophin (hCG) can be assayed in specimens obtained by percutaneous fetal blood sampling to check for the absence of maternal blood or amniotic fluid contamination. In order to assess the accuracy of this approach, we measured serum hCG in 44 pure fetal blood samples obtained by intracardiac puncture. The mean fetal serum hCG concentration was 52 IU/l, and the ratio of maternal to fetal serum hCG concentration never exceeded 1 · 1 per cent, which represents the smallest contamination rate detectable by this method.  相似文献   
975.
Transvaginal chorionic villus sampling (CVS) using concurrent transabdominal ultrasound guidance was performed in six women who desired CVS but could not be offered transcervical or transabdominal approaches because of uterine position and placental location. Satisfactory amounts of chorionic villi were obtained in all six cases with no maternal discomfort, an occurrence that contrasts with our experience in transvaginal CVS using endovaginal ultrasound guidance. We believe that transvaginal CVS using concurrent transabdominal ultrasound guidance warrants consideration as an alternative technique for first-trimester CVS in selected patients.  相似文献   
976.
A prenatal diagnosis was carried out on a 9-week-old fetus at risk for autosomal dominant polycystic kidney disease (ADPKD). Ten members of the family were previously typed using five DNA markers linked to the PKD1 locus on chromosome 16, and one marker linked to the putative PKD2 locus on chromosome 2. The polymerase chain reaction (PCR) was used to amplify the D16S125 locus. Pairwise and multipoint lod scores indicated that the family was most likely segregating a PKD1 mutation. The fetus inherited the disease haplotype from the affected parent. Diagnostic accuracy was greater than 99 per cent, taking into account the possibility of genetic heterogeneity.  相似文献   
977.
Chorionic villus sampling was performed on two patients with a previous family history of Sandhoff's disease. Total β-hexosaminidase (Hex) activity in case 1 was within the normal range (case 1: 6365 μmol/h/g protein; control range: 3227-24 495/miol/h/g protein). The β-hexosaminidase isoenzyme pattern was found to be normal. These results were confirmed on cultured amniotic fluid cells. In case 2, the total Hex activity was 672 μmol/h/g protein, i.e., 7 per cent of the control mean (10 085 μmol/h/g protein), and chromatography demonstrated that more than 50 per cent of this activity was due to the abnormal isoenzyme β-hexosaminidase S (Hex S). The fetus was predicted to be affected by Sandhoff's disease and this was confirmed on fetal tissues after termination of pregnancy. This study demonstrates that a fetus affected by Sandhof's disease can be reliably diagnosed during the first trimester of pregnancy.  相似文献   
978.
污染几率原则用于近岸海域大气采样点的选位   总被引:1,自引:0,他引:1  
应用污染几率原则,选择在沿岸地区最大污染几率的上风方位设方大气采样点,通过实验分析并与盛行风,污染风原则选位结果比较表明,该原则具有显著实用性。  相似文献   
979.
On consultation, percutaneous umbilical blood sampling (PUBS) was offered to women with immune thrombocytopenic purpura (ITP) to determine the mode and site of delivery prior to labour. Between January 1989 and December 1993, 41 pregnant women underwent PUBS. All women had a history of ITP, a platelet count less than 90 K, (+) antiplatelet antibody, and/or thrombocytopenia diagnosed early in pregnancy. PUBS was performed at term except in one patient with preterm labour, who underwent PUBS at 31 weeks' gestation. Patients with fetal platelet counts greater than 50 K returned to their referring physician for delivery. Records were complete in 39 pregnancies. Fetal blood was successfully obtained in 37 of 39 cases (95 per cent). Fetal platelet counts correlated with neonatal platelet counts in 36 of 37 cases (97 per cent). The interval between PUBS and delivery ranged from 0 to 31 days. Six of 37 fetuses (16 per cent) had significant fetal thrombocytopenia (<50 K). These six patients underwent Caesarean section. Vaginal delivery was recommended in all others. There were two procedure-related complications. There were no cases of intraventricular haemorrhage in any of the neonates. In conclusion, there is a high incidence of fetal thrombocytopenia in women with ITP. PUBS reliably detects fetal thrombocytopenia and is therefore useful in the perinatal planning of the mode and site of delivery.  相似文献   
980.
Neonatal alloimmune thrombocytopenia (NAIT), which usually involves sensitization to P1A1 (HPA-1a), may have devastating complications for the fetus. These may be prevented by antenatal treatment of severe cases with either maternally administered high-dose gamma-globulin and/or repeated intrauterine platelet transfusions. Determination of the paternal platelet phenotype is useful for counselling parents who have had one or more affected pregnancies. This report of an unaffected pregnancy in a woman with a history of previous pregnancies complicated by NAIT illustrates the role of paternal and fetal platelet phenotyping in managing existing pregnancies at risk of NAIT.  相似文献   
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