简介:目的探讨云浮市育龄期妇女全血微量元素与孕妇在不同孕期微量元素的变化规律,掌握该地区孕妇必需微量元素的缺乏状况,有害元素含量,制定干预措施。方法随机抽取100名育龄期妇女做为对照组,按孕周将300名孕妇分为早孕、中孕、晚孕3个实验组,采用原子吸收光谱法测定孕妇及对照组妇女全血铜、锌、钙、镁、铁微量元素及有害元素铅的含量。结果除育龄期妇女与怀孕妇女铅元素无统计学意义(P〉0.05)外;钙镁铁锌铜的含量有明显的不同,并随着孕期的增加,呈一定的规律变化,铜逐渐升高,钙镁铁锌逐渐降低的。结论要加强围产期的保健工作,定期进行微量元素监测,根据不同孕周及其变化的规律,通过合理饮食搭配和补充微量元素,注意避免过多的铅接触,以保证母婴健康,达到优生优育的目的。
简介:AIM:Todescribethecharacteristicsofmodulationtransferfunction(MTF)ofanteriorcornealsurface,andobtainthethenormalreferencerangeofMTFatdifferentspatialfrequenciesandopticalzonesoftheanteriorcornealsurfaceinmyopes.·METHODS:Fourhundredeyesfrom200patientswereexaminedunderSIRIUScornealtopographysystem.PhoenisanalysissoftwarewasappliedtosimulatetheMTFcurvesofanteriorcornealsurfaceatverticalandhorizontalmeridiansatthe3,4,5,6,7mmopticalzonesofcornea.TheMTFvaluesatspatialfrequenciesof5,10,15,20,25,30,35,40,45,50,55and60cycles/degree(c/d)wereselected.·RESULTS:TheMTFcurveofanteriorcornealsurfacedecreasedrapidlyfromlowtointermediatefrequency(0-15cpd)atvariousopticalzonesofcornea,thevaluedecreasedto0slowlyathigherfrequency(>15cpd).Withtheincreaseoftheopticalzonesofcornea,MTFcurvedecreasedgradually.3)Intherangeof3mm-6mmopticalzonesofthecornea,theMTFvaluesmeasuredathorizontalmeridianweregreaterthanthecorrespondingvaluesathorizontalmeridianofeachspatialfrequency,thedifferencewasstatisticallysignificant(P<0.05).At7mmopticalzonesofcornea,theMTFvaluesmeasuredathorizontalmeridianwerelessthanthecorrespondingvaluesatverticalmeridianat10-60spatialfrequencies(cpd),andthedifferencewasstatisticallysignificantin25,30,35,40,45,50cpd(P<0.05).·CONCLUSION:MTFcanbeusedtodescribetheimagingqualityofopticalsystemsatanteriorcornealsurfaceobjectivelyindetail.