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Russian Journal of Ecology - Populations at the border of ranges are considered more vulnerable than those in the center. However, some recent reviews contradict this hypothesis. We have studied... 相似文献
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Duodenal stenosis associated with oesophageal atresia was diagnosed by ultrasound at 12 weeks' gestation. The diagnosis was made by recognition of a double bubble sign which was more pronounced when a vaginal transducer was used. Post-abortion autopsy confirmed the diagnosis. Oesophageal and duodenal obstruction in this case had no effect on the amount of amniotic fluid or the alpha-fetoprotein concentration since swallowing and subsequent utilization of amniotic fluid do not occur before 12 weeks of gestation. 相似文献
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Russian Journal of Ecology - 相似文献
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