基于交直轴电流耦合的单电流调节器永磁同步电机弱磁控制

基于交直轴电流耦合的单电流调节器弱磁控制是一种新颖的永磁同步电机弱磁策略，能够解决双电流调节器在电机高速域相互冲突而易于饱和的问题。交轴电压指令如何确定是此方法的研究重点，直接影响电机的电压利用率、效率以及负载能力。该文基于电机电压方程对电流耦合调节弱磁控制基本原理进行描述，并提出改进的控制方法。利用id-iq坐标平面上的定子电流轨迹，对现有方法的缺点和所提出方法的预期控制效果进行了分析。在小信号范围内，对所提出方法的动态控制过程和可控性进行了阐述。所提出的电流耦合调节变交轴电压弱磁控制策略，交轴电压指令根据电机工况自行调节，无需查表，且不依赖电机参数，易于实现。仿真和实验结果验证了所提方法的可行性和性能优势。     

Scientific Sessions (SS)

European Radiology -     

Early detection of cardiotoxicity by 3D speckle tracking imaging of area strain in breast cancer patients receiving chemotherapy

Eighty‐three breast cancer patients who underwent six cycles of EC chemotherapy regimen (epirubicin + cyclophosphamide) without symptoms and signs of heart disease were enrolled in the study. Three‐dimensional speckle tracking imaging technique (3D‐STI) was used to measure left ventricular global area strain (GAS), overall annular strain (GCS), overall longitudinal strain (GLS), and overall radial strain (GRS). Meanwhile, serum troponin T (Hs‐cTnT) was measured. The clinical value of each index on cardiotoxicity after chemotherapy was analyzed using the receiver operating characteristic (ROC) curve. Hs‐cTnT increased from the early stage to the end during chemotherapy, but it was still in the normal range. During the mid‐chemotherapy and the end‐chemotherapy, GAS, GLS, GCS, and E/A significantly reduced, while the changes in LVESV, LVEDV, LVEF, and GRS were not significant after chemotherapy. Pearson correlation analysis showed a significant negative correlation between GAS and anthracycline doses (r = ?.772, P < .01); GAS and Hs‐cTnT were significantly negatively correlated (P < .05). The area under the curve (AUC) of GAS, GLS, GCS, and GRS are 0.815, 0.683, 0.645, and 0.585, respectively. A GAS of ?31.5% was used as the cutoff value for diagnosing left ventricular systolic dysfunction after receiving chemotherapy. The sensitivity of the previous parameters was 81.9%, and the specificity was 80.3%. Interobserver consistency analysis showed that 3D‐STI strain parameter measurement has good repeatability. GAS has greater value in predicting early myocardial damage after anthracycline chemotherapy.     

Alantolactone,a sesquiterpene lactone,inhibits breast cancer growth by antiangiogenic activity via blocking VEGFR2 signaling

Alantolactone (ALA), a sesquiterpene lactone isolated from several medicinal plants such as Inula helenium, has been identified to have attractive anticancer activity. However, its role in the inhibition of angiogenesis during tumor development remains unclear. In this study, we found ALA can inhibit the proliferation, motility, migration, and tube formation of human umbilical vein endothelial cells. ALA also restrained angiogenesis in chick embryo chorioallantoic membrane and delayed the growth of human MDA‐MB‐231 breast cancer xenograft in mice through angiogenesis inhibition. Furthermore, ALA suppressed the phosphorylation of vascular endothelial growth factor receptor 2 and its downstream protein kinase including PLCγ1, FAK, Src, and Akt in endothelial cells. Taken together, the antiangiogenic activity of ALA and its molecular mechanism are identified for the first time, indicating that ALA may be a potential drug candidate or lead compound for antiangiogenic cancer therapy.     

基于重水拉曼技术评价口腔抑菌剂对粪肠球菌抑菌效能的研究

目的:开发有效且对患者副作用小的口腔抑菌剂配方,系统评价过氧化氢(hydrogen peroxide,H2O2)、次氯酸钠(Sodium hypochlorite,NaClO)对粪肠球菌(Enterococcus faecalis ATCC29212)的抑菌效能.方法:分别采用肉汤稀释法和重水拉曼技术(D2O-labeled single-cell Raman micro-spectroscopy),通过最小抑菌浓度(minimum inhibitory concentration,MIC)和最低抑制代谢浓度(minimum inhibitory concentration based on metabolic activity,MIC-MA)定量评价了抑菌剂对粪肠球菌的生长和代谢抑制作用.结果:对于过氧化氢和次氯酸钠,MIC分别为110 mg/L和0.45 g/L,尽管生长完全停止,但细菌细胞的代谢活性在8 h平均降低了71％、70％,显示出一种"非生长但代谢活跃"(NGMA)的状态,这种状态可能导致潜在的难治性反复感染.而MIC-MA分别为220 mg/L和0.9 g/L时,所有细胞的代谢活动在暴露8 h后完全停止.此外,NaClO+H2O2的组合使用优于单独使用次氯酸钠、过氧化氢.结论:MIC-MA有利于严格评估抗细菌疗效,NaClO+H2O2可作为细菌病原体更有效的抑菌剂方案.