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471.
A simple high resolution technique for human chromosomes is described for fibroblasts obtained from amniotic fluid cell cultures. The application and clinical significance of this technique in prenatal diagnosis is discussed. 相似文献
472.
Carlo Gualtieri 《Environmental Fluid Mechanics》2006,6(1):1-24
Mass-transfer processes of paramount importance, such as reaeration and volatilization, occur at the air–water interface.
Particularly, volatilization is intensively studied because it can be a relevant removal process for toxic contaminants from
flowing and standing surface waters. The paper provides a comparison among predictive equations available from literature
for standing waters for the case of MTBE contamination. Most of the considered equations tend to overestimate the volatilization
rate, while three equations offer a good fit with the observed data. Finally, these equations are applied to a larger amount
of field data. 相似文献
473.
This study investigates whether cell-free amniotic fluid facilitates cell attachment to the surface of culture plates and thereby promotes rapid amniocyte growth. Isolated or pooled cell-free amniotic fluid samples at different volumes were added to culture plates. Trypsinized subcultures, grown in Eagle's minimum essential alpha medium supplemented with fetal bovine serum (4–20 per cent), were monitored by cell counts. The results demonstrated growth stimulation on culture plates precoated with amniotic fluid. The minimal time for coating the culture plates was 6h. Maximal coating was observed after an overnight incubation with 2–3 ml of the fluid per culture vessel. No synergistic effect from addition of fetal bovine serum to amniotic fluid was observed. A freshly coated surface provided the best amniocyte growth. When primary cultures are grown on a precoated surface, there is an increase in colony counts in 80 per cent of the samples tested. This method may be used to improve amniocyte growth, especially in samples with relatively small numbers of cells. 相似文献
474.
The media from primary cultures and subcultures of second trimester human amniotic fluid (AF) cells were assayed by radioimmunoassay to quantitate production of human chorionic gonadotropin (hCG). Primary AF cultures produce more hCG per cell than do the corresponding subcultures. Sodium butyrate (2 mM) stimulates AF subcultures to produce 5-13 times more hCG per cell or per mg of cellular protein than do untreated subcultures. This stimulatory effect of sodium butyrate is dose dependent between 0 and 5 mM. Addition of sodium butyrate 24 hours after subculture, while stimulating production of hCG during the subsequent 3 days, also results in fewer cells and less protein per culture. This effect on cell growth is also dose-dependent. Previous investigators have proposed that the stimulation of hCG by sodium butyrate in other types of cell cultures is due to an effect of that agent on culture growth. Therefore, in these studies AF cells are allowed to grow to confluency before sodium butyrate was added. Production of hCG was stimulated by sodium butyrate about four-fold during the next 5 days although no significant changes were observed either in number of cells or amount of cellular protein per culture. These results suggest that stimulation of hCG by sodium butyrate is not dependent on its effect on growth of the cultures. 相似文献
475.
油藏流体状态方程研究具有重要的理论和现实意义 ,它将成为流体热力学研究的一个新的生长点。论文从流体状态方程的推导方法、影响因素、主要类型等方面较系统地论述了油藏流体状态方程的研究思路和发展方向。并且从含油气系统中烃类相态的判断、油气藏类型的识别以及确定储层质量评价的物理化学模型等方面总结了其研究成果的应用进展。它将为油气藏成藏机理物理化学模型的建立和合理开发方案的制定提供新的工具 相似文献
476.
K.B McGrattan 《Spill Science & Technology Bulletin》2003,8(4):367-372
A combination of numerical modeling and large-scale experimentation has yielded a tremendous amount of information about the structure, trajectory and composition of smoke plumes from large crude oil fires. A numerical model, a large outdoor fire plume trajectory (ALOFT), has been developed at NIST to predict the downwind concentration of smoke and other combustion products. The model is based on the fundamental conservation equations that govern the introduction of hot gases and particulate matter from a large fire into the atmosphere. The model has been used to estimate distances from fires under of variety of meteorological and topographic conditions where ground level concentrations of smoke and combustion products fall below regulatory threshold levels. 相似文献
477.
超临界流体技术在化工污染治理中的应用 总被引:4,自引:0,他引:4
对于许多化工产品废物,如塑料、有毒物质、生物污泥和有机废水等,利用传统技术进行处理的效果较差。超临界流体(SCF)技术作为一种清洁环境的新技术,可用于治理化工污染物。SCF作为反应介质或反应物可替代有毒、有害有机溶剂;用作萃取剂,它是一种新型的分离技术;以SCF作移动相的色谱,可提高检测灵敏度和分辨率;将超临界水作为氧化剂,可破坏有机污染物的结构。SCF技术的应用可以大大减少环境污染。 相似文献
478.
479.
480.
The Bhopal disaster was a gas leak incident in India, considered the world's worst industrial disaster happened around process facilities. Nowadays the process facilities in petrochemical industries have becoming increasingly large and automatic. There are many risk factors with complex relationships among them. Unfortunately, some operators have poor access to abnormal situation management experience due to the lack of knowledge. However these interdependencies are seldom accounted for in current risk and safety analyses, which also belonged to the main factor causing Bhopal tragedy. Fault propagation behavior of process system is studied in this paper, and a dynamic Bayesian network based framework for root cause reasoning is proposed to deal with abnormal situation. It will help operators to fully understand the relationships among all the risk factors, identify the causes that lead to the abnormal situations, and consider all available safety measures to cope with the situation. Examples from a case study for process facilities are included to illustrate the effectiveness of the proposed approach. It also provides a method to help us do things better in the future and to make sure that another such terrible accident never happens again. 相似文献