Objective: To construct an animal model of chronic ischemic myocardium, and evaluate it by ultrasonic integrated backscatter (IBS) and Doppler tissue imaging (DTI). Methods: An Ameroid constrictor was placed around th...Objective: To construct an animal model of chronic ischemic myocardium, and evaluate it by ultrasonic integrated backscatter (IBS) and Doppler tissue imaging (DTI). Methods: An Ameroid constrictor was placed around the porcine left circumflex coronary artery (LCX). The calibrated average image intensity (%AII), cyclic variation of IBS (CVIB), transmural gradient index (TGI) of CVIB in lateral-posterior wall (LPW), and DTI spectrum of LPW in left ventricular papillary muscle level short axis view (LVPM-SAM) and apical four chamber view (AP-4CV) at normal state, 2, 4, 6 and 8 weeks postoperatively were measured. Results: Normal %AII, CVIB and TGI were 2.29±0.32, 9.69±2.22dB and 0.22±0.08, respectively. The %AII increased gradually postoperatively. The CVIB decreased also gradually, and the decrease was higher in subepicardium than in subendocardium. Most of TGI decrease occurred from 2 to 4 weeks postoperatively and became zero at 8 weeks (P<0.01); Normal V S (peak systolic velocity) of AP-4CV was higher than that of LVPM-SAM (P<0.01). V E (peak early diastolic velocity) of AP-4CV was lower than that of LVPM-SAM (P<0.05). V S and V E were all decreased after operation (P<0.01). The decrease of V S in AP-4CV was greater than that in LVPM-SAM. Conclusion: The pathological changes of the myocardium in human ischemic heart disease (IHD) are similar to that of Ameriod model. IBS and DTI can detect echo changes and ventricular wall motion in chronic ischemic myocardium, and provide more information for clinical investigation and treatment of IHD.展开更多
In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To...In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To mimic these structural colors,based on periodic semicircular micro-grooved(PSMG) substrate,silica colloidal photonic crystals provide anisotropic angle-independent structural colors.The PSMG photonic crystals were fabricated by self-assembling monodispersed silica nanoparticles on a micro-grooved template,which can be easily prepared in large scale by a hot embossing method,and no additional materials are needed in the whole preparation process.The PSMG photonic crystals exhibit identical structural colors around the groove axis,whereas it is angle-dependent along the groove axis.In addition,this PSMG surface of photonic crystal also leads to color separation effect and monocolor polarization conversion.This system provides a facile and scalable means to prepare anisotropically angleindependent colloidal photonic crystal,which is considered important in applications in the field of anti-counterfeiting or the manufacture of monochromatic light reflector with wide viewing angles and other novel optical devices.展开更多
文摘Objective: To construct an animal model of chronic ischemic myocardium, and evaluate it by ultrasonic integrated backscatter (IBS) and Doppler tissue imaging (DTI). Methods: An Ameroid constrictor was placed around the porcine left circumflex coronary artery (LCX). The calibrated average image intensity (%AII), cyclic variation of IBS (CVIB), transmural gradient index (TGI) of CVIB in lateral-posterior wall (LPW), and DTI spectrum of LPW in left ventricular papillary muscle level short axis view (LVPM-SAM) and apical four chamber view (AP-4CV) at normal state, 2, 4, 6 and 8 weeks postoperatively were measured. Results: Normal %AII, CVIB and TGI were 2.29±0.32, 9.69±2.22dB and 0.22±0.08, respectively. The %AII increased gradually postoperatively. The CVIB decreased also gradually, and the decrease was higher in subepicardium than in subendocardium. Most of TGI decrease occurred from 2 to 4 weeks postoperatively and became zero at 8 weeks (P<0.01); Normal V S (peak systolic velocity) of AP-4CV was higher than that of LVPM-SAM (P<0.01). V E (peak early diastolic velocity) of AP-4CV was lower than that of LVPM-SAM (P<0.05). V S and V E were all decreased after operation (P<0.01). The decrease of V S in AP-4CV was greater than that in LVPM-SAM. Conclusion: The pathological changes of the myocardium in human ischemic heart disease (IHD) are similar to that of Ameriod model. IBS and DTI can detect echo changes and ventricular wall motion in chronic ischemic myocardium, and provide more information for clinical investigation and treatment of IHD.
基金supported by the National Key Research and Development Program of China(2016YFA0200800, 2013CB834505)he National Natural Science Foundation of China(U1430128,21503244)
文摘In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To mimic these structural colors,based on periodic semicircular micro-grooved(PSMG) substrate,silica colloidal photonic crystals provide anisotropic angle-independent structural colors.The PSMG photonic crystals were fabricated by self-assembling monodispersed silica nanoparticles on a micro-grooved template,which can be easily prepared in large scale by a hot embossing method,and no additional materials are needed in the whole preparation process.The PSMG photonic crystals exhibit identical structural colors around the groove axis,whereas it is angle-dependent along the groove axis.In addition,this PSMG surface of photonic crystal also leads to color separation effect and monocolor polarization conversion.This system provides a facile and scalable means to prepare anisotropically angleindependent colloidal photonic crystal,which is considered important in applications in the field of anti-counterfeiting or the manufacture of monochromatic light reflector with wide viewing angles and other novel optical devices.
