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421.
Chinese life cycle impact assessment factors   总被引:5,自引:0,他引:5  
IntroductionLifecycleassessment(LCA)isanenvironmentalmanagementtoolthatisusedtoexamineandevaluatetheenvironmentalimpactsassociatedwiththeexistenceofproducts(Jensen,1998;Weidema,1997;Wenzel,1997).ThefocusofLCAisontheentirelifecycleoftheproduct,i.e.fromtheextracti…  相似文献   
422.
IntroductionChengdu KunmingRailwayLineislocatedonthemountainregionofsouthwesternChina .Therearealotofdebrisflowgulliesspreadingbesidethisrailwayline .Onsummer,thedebrisflowoftenburstsandthreatensthesafetyoftherailwaytransportation.In 1981,alarge scaledebris…  相似文献   
423.
Ten out of the 12 new EU members, used to belong to the so-called “former eastern block”, with a post WWII environmental policy radically different from the tendencies followed in Western Europe. The lack of conservation regulations has resulted in a rather harmful industrialization, regarding natural resources and environmental quality. While air pollution transfer is a phenomenon of transboundary level, there is a particular interest in examining the contribution of the new EU member states to the environmental pressure faced by the older member states and vice versa. The current study utilises the official data for almost 20 years published by the European Monitoring and Evaluation Program concerning the transboundary transfer of NOx and SO2 in order to analyse the situation and discuss the present and future environmental policy regarding air pollution.  相似文献   
424.
A multiple pregnancy of high rank may occur in a couple at risk for a Mendelian disorder. Prenatal diagnosis is hampered by the difficulty of (1) obtaining chorionic villi from each zygote arid (2) unequivocally relating each sample to the corresponding embryo. The calculation of the genetic risk according to the number of zygotes led us to propose a diagnostic strategy based on embryo reduction, a technique initially designed to improve the perinatal outcome of multiple pregnancies with normal embryos. We report a case in which this approach allowed rational use of first-trimester chorionic villus sampling in a quintuplet pregnancy at risk for non-ketotic hyperglycinaemia, resulting in the selective birth of unaffected twins.  相似文献   
425.
A case is described of the prenatal diagnosis of choroid plexus cysts at 17 weeks' gestation which persisted beyond 36 weeks but could not be detected after delivery. At birth the child was found to have trisomy 18.  相似文献   
426.
A number of different models of CF carrier screening have now been tested in pilot trials. Apart from opportunistic and cascade testing (which are strictly speaking not true forms of screening), the major programmes have been directed either to young adults in primary care or to pregnant women in antenatal clinics. Only in the latter form of screening has sufficient data been collected to allow conclusions to be reached on the optimum mode of delivery. It seems very probable that when CF carrier screening passes into routine service, it will be the antenatal couple model that is used.  相似文献   
427.
We report the first prenatal diagnosis of an affected fetus with Chediak-Higashi syndrome (CHS). Diagnosis was accomplished via fetal blood sampling at 17 menstrual weeks and was confirmed after birth. Retrospective measurement of the largest acid phosphatase-positive lysosomes in cultured amniotic fluid cells and chorionic villus cells showed that in CHS these lysosomes are significantly larger than those in normal cells. This method may be used for prenatal diagnosis of CHS by amniocentesis and chorionic villus sampling (CVS).  相似文献   
428.
As part of the Medical Research Council randomized trial of vitamin supplementation in the prevention of neural tube defects (NTDs), maternal serum alpha-fetoprotein (AFP) was available for 19 NTD pregnancies. Each of these was matched with four unaffected controls, by maternal age, participating centre, and duration of sample storage. The samples came from women whose gestational age ranged from 6 to 14 completed weeks. The median AFP level in the affected pregnancies was 1·2 multiples of the median value in unaffected pregnancies of the same gestational age (95 per cent confidence interval (CI) 0·83–1·59). This confirmed the view that serum AFP measurement is of no practical value in the detection of NTDs in the first trimester of pregnancy. The study also showed that folic acid supplementation, used as a method of preventing NTDs, had no effect on the concentrations of maternal serum AFP up to 14 weeks of pregnancy.  相似文献   
429.
430.
This paper considers relationships between sustainability objectives, transport, spatial design of the built environment and rational use of energy. Conventional transport modelling, housing supply and energy assessment tools are drawn together to provide a common platform for appraisal of city-wide energy use by stationary and mobile sources. The paper outlines methodologies developed for the city of Belfast, Northern Ireland. The paper concludes by briefly reviewing the effect in terms of mobile and stationary energy consumption and travel behaviour of implementing sustainable policy measures in current and future years within the study area.  相似文献   
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