简介:Euphausiapacificisanimportantsourceofnaturalastaxanthin.StudieswerecarriedouttoassesstheextractabilityofastaxanthinfromE.pacificusingsubcritical1,1,1,2-tetrafluoroethane(R134a).Toexaminetheeffectsofmultipleprocessvariablesontheextractionyield,astaxanthinwasextractedundervariousconditionsofpressure(30-150bar),temperature(303-343K),time(10-50min),flowrate(2-10gmin-1),moisturecontent(5.5%-63.61%),andparticlesize(0.25-0.109mm).Theresultsshowedthattheextractionyieldincreasedwithtemperature,pressure,timeandflowrate,butdecreasedwithmoisturecontentandparticlesize.Amaximumyieldof87.74%wasobtainedunderconditionsof100bar,333K,and30minwithaflowrateof6gmin-1andamoisturecontentof5.5%.Thesubstantialastaxanthinyieldobtainedunderlow-pressureconditionsdemonstratesthatsubcriticalR134aisagoodalternativetoCO2forextractionofastaxanthinfromE.pacific.
简介:目的研究新生儿CYP1A1、GSTM1、GSTT1基因的多态性分布,为新生儿建立相应基因型记录,达到防病治病的目的。方法收集新生儿脐血,抽提其中有核细胞的DNA,PCR扩增CYP1A1、GSTM1、GSTT1基因的特征性外显子片段。限制酶切CYP1A1扩增产物,RFLP分析每个标本的基因型;非变性聚丙稀酰胺凝胶电泳分析GSTM1、GSTT1的基因型。结果CYP1A1、GSYM1和GSTT1基因型均成多态性分布,CYP1A1的基因型分布有3种,分别为A/A基因型占60.9%、A/G基因型占34.5%、G/G基因型占4.5%;GSTM1的基因型有2种分别为GSTM1+/+和GSTM1+/0占85.5%、GSTM1-/-占14.5%。GSTT1基因型分布为GSTT1+/+和GSTT1+/0占76.1%,GSTT10/0为23.6%。结论在正常出生的新生儿中,他(她)们的代谢酶CYP1A1、GSTM1、GSTT1基因存在着多态性分布的现象。