双酚A诱导内质网应激致甲状腺功能损害的作用机制研究

目的观察双酚A(Bisphenol A,BPA)染毒对成年雌性大鼠甲状腺功能的影响及甲状腺内质网应激机制在该过程中的作用。方法选用40只SD雌性大鼠,随机分为4组,分别经口灌胃给予玉米油(溶剂对照)和BPA,剂量分别为0.05、0.5和5 mg/kg·bw。10周时,麻醉处死动物并留取样品进行检测。采用实时荧光定量PCR法检测TG mRNA表达水平,采用蛋白质印迹法检测甲状腺球蛋白(thyroglobulin,TG)和内质网应激相关蛋白的表达水平的变化,采用苏木素-伊红(HE)染色进行甲状腺组织学检测及使用透射电子显微镜观察甲状腺滤泡细胞内的内质网结构的变化。结果BPA染毒可使实验动物血浆T3、T4和TG水平明显升高,低和中剂量染毒可明显上调甲状腺组织TG mRNA转录水平(P_(T3)=0.004,P_(T4)<0.001,PTG<0.001,PTG mRNA=0.001),并可致T3/T4比值明显下降,差异均有统计学意义(P<0.001)。Western blot检测结果显示BPA染毒可明显上调内质网应激中GRP78、ATF6和IRE1α蛋白水平(P_(GRP78)=0.008,P_(ATF6)=0.016,PIRE1α=0.001)。结论BPA染毒可诱导甲状腺功能紊乱,其中ATF6和IRE1通路激活及内质网应激可能是其机制之一。

Analysis of armature reaction and winding inductances of permanent magnet brushless DC motor with deep slot concentrated coils

Based on the configuration of deep slot concen-trated coils,an analytical model is developed for predicting the armature reaction field produced by the 3-phase stator windings of permanent magnet brushless DC motors with concentrated coils by using the image method and the ana-lytical functions of the armature reaction and winding in-ductances are proposed accounting for the influence of sta-tor slotting.This approach is different from the method of equivalent distributed current sheet and more suitable for electric machines,which have concentrated coils and deeper slots.Under different control mode,the different analytical functions are presented.This will be helpful when further analyzing the performance of the motor.The results agree with the experiment very well.