{"title":"Temperature gradients in the microwave-irradiated egg: implications for avian teratogenesis.","authors":"R L Clarke, D R Justesen","doi":"10.1080/16070658.1983.11689322","DOIUrl":null,"url":null,"abstract":"<p><p>Five experiments were performed on a total of 60 non-fertile eggs of Gallus gallus to determine the spatial character, persistence, and physical basis of thermal gradients after a 300-s exposure to the intense, multipath, 2.45-GHz yield of a multimode cavity (dose rates: approximately 80 to 120 mW/g). After irradiation of an intact egg that was first equilibrated to the ambient temperature, a 3-mm diameter Plexiglas rod, which was fitted with junctions of four microwire thermocouples at 10-mm intervals, was inserted to place the distal junction in the approximate center of the yolk, the most proximal junction in peripheral thin white. Temperatures measured immediately after irradiation revealed a highly reliable linear gradient of mean temperatures from central yolk to peripheral white (P less than 0.001). The gradient was also highly persistent: Mean temperatures of central yolk exceeded those of outer thin white by more than 4 degrees C 5 minutes after irradiation, and by more than 2 degrees C 60 minutes afterward. In contrast, when an egg's contents were mixed before irradiation, the gradient was effectively eliminated. A previous report of athermally induced (field-specific) teratogenesis in chick embryos is placed under an interpretive cloud by the present findings: Terata emerged from eggs that were structurally intact during microwave irradiation, but estimates of maxima of embryonic temperatures were based on thermal measurements of non-fertile eggs the contents of which had been mixed by a thermal probe before irradiation.</p>","PeriodicalId":76653,"journal":{"name":"The Journal of microwave power","volume":"18 2","pages":"169-80"},"PeriodicalIF":0.0000,"publicationDate":"1983-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/16070658.1983.11689322","citationCount":"10","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of microwave power","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/16070658.1983.11689322","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 10
Abstract
Five experiments were performed on a total of 60 non-fertile eggs of Gallus gallus to determine the spatial character, persistence, and physical basis of thermal gradients after a 300-s exposure to the intense, multipath, 2.45-GHz yield of a multimode cavity (dose rates: approximately 80 to 120 mW/g). After irradiation of an intact egg that was first equilibrated to the ambient temperature, a 3-mm diameter Plexiglas rod, which was fitted with junctions of four microwire thermocouples at 10-mm intervals, was inserted to place the distal junction in the approximate center of the yolk, the most proximal junction in peripheral thin white. Temperatures measured immediately after irradiation revealed a highly reliable linear gradient of mean temperatures from central yolk to peripheral white (P less than 0.001). The gradient was also highly persistent: Mean temperatures of central yolk exceeded those of outer thin white by more than 4 degrees C 5 minutes after irradiation, and by more than 2 degrees C 60 minutes afterward. In contrast, when an egg's contents were mixed before irradiation, the gradient was effectively eliminated. A previous report of athermally induced (field-specific) teratogenesis in chick embryos is placed under an interpretive cloud by the present findings: Terata emerged from eggs that were structurally intact during microwave irradiation, but estimates of maxima of embryonic temperatures were based on thermal measurements of non-fertile eggs the contents of which had been mixed by a thermal probe before irradiation.