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81.
We present a remarkable chain of events in which percutaneous umbilical cord sampling was performed in an attempt to clarify a situation of possible fetal sex chromosome mosaicism in an amniotic fluid culture and led to the discovery that the mother herself had a 45,X/46,XX/ 47.XXX chromosome constitution. This may have simply represented the chance concurrence of pseudo-mosaicism in the amniotic fluid culture of a woman with an abnormal sex chromosome constitution, but it is also possible that the 45,X colony was maternal in origin. Although clearly a most unusual circumstance, the possibility should be kept in mind when termination of a pregnancy is being considered because of apparent mosaicism in a prenatal diagnostic study. 相似文献
82.
介绍由一级动力学模式推导废水处理实用公式。文中探讨了20℃降解速率系数K20和温度修正系数θ,仅是某种水质和生化条件下的对应值,不能任意通用。 相似文献
83.
H. Brandenburg MD W. De Koning M. G. J. Jahoda Th. Stijnen M. A. J. De Ridder E. S. Sachs J. W. Wladimiroff 《黑龙江环境通报》1992,12(12):1031-1035
One hundred and fifty-one women of advanced maternal age who underwent genetic termination of pregnancy (TOP) were studied for their reproductive behaviour and the type of procedure for prenatal diagnosis in a subsequent pregnancy. A total of 59 women (39 per cent) had a further pregnancy. In all continuing pregnancies prenatal diagnosis was performed, of which 75 per cent consisted of chorionic villus sampling (CVS). Reproductive behaviour following a genetic termination was negatively correlated with maternal age and parity. Both reproductive behaviour and the choice to undergo a diagnostic procedure in the next pregnancy were independent of the type of diagnostic procedure in the previous affected pregnancy. 相似文献
84.
W. F. Carey A. Poulos P. Sharp P. V. Nelson E. F. Robertson J. L. Hughes A. Gill 《黑龙江环境通报》1994,14(9):813-819
Variability in the level of expression of very long chain fatty acids (VLCFAs) is documented in cultured chorionic villus (CV) cells derived from two fetuses, one at risk for an unusual peroxisomal fatty acid β-oxidation defect, and the other at risk for the X-linked form of adrenoleucodystrophy (ALD). Cells from early subcultures of chorionic cells from both cases gave normal values for VLCFA ratios. The results for the fetus at risk for the β-oxidation defect were interpreted to indicate that the fetus was not affected; however, at birth, the infant was clinically and biochemically affected. In the case of the fetus at risk for X-linked ALD, although VLCFAs were normal in subculture 1, the levels of these fatty acids increased dramatically in subculture 3, suggesting an abnormal fetus. Termination of the pregnancy and subsequent biochemical and morphological follow-up confirmed that the fetus was indeed affected by ALD. 相似文献
85.
86.
A new approach applying fuzzy mathematic theorems, including the Primary Matrix Element Theorem and the Fisher Classification Method, was established to solve the optimization problem of atmospheric environmental sampling sites. According to its basis, an application in the optimization of sampling sites in the atmospheric environmental monitoring was discussed. The method was proven to be suitable and effective. The results were admitted and applied by the Environmental Protection Bureau (EPB) of many cities of China. A set of computer software of this approach was also comuletelv comniled and used. 相似文献
87.
通过对元宝山露天矿疏干水现存问题的探讨 ,对问题成因进行分析 ,找出解决问题的的具体办法 ,为露天疏干水建设提供模型 相似文献
88.
沙尘天气对沈阳市空气质量的影响分析 总被引:3,自引:0,他引:3
针对沙尘天气的成因、来源及危害进行综述 ,对沈阳市 2 0 0 2年出现的沙尘天气特点及对空气质量影响进行了分析 ,提出几点防治对策 相似文献
89.
90.
Preparation of PFS coagulant by sectionalized reactor 总被引:3,自引:0,他引:3
The oxidation rate of ferrous sulfate is investigated for the preparation of polyferric sulfate(PFS)coagulant.In is proved that this reaction is zero order with respect to Fe^2 ,first order with respect to NO2(g),and first order with respect to the interface area between gas phase and liquid phase.According to this mechanism,sectionalized reactor(SR) is used in place of traditional reactor(TR),and the liquid of reaction mixture is recycled by pump.As a result,not only the flow path of reaction liquid is prolonged,but also gas-liquid contact area enlarged,and the reaction distinctly accelerated,compared with traditional reactor.The effects of parameters including temperature,acidity and others on the reaction rate are also discussed. 相似文献