Review: optically-triggered phase-transition droplets for photoacoustic imaging

Optically-triggered phase-transition droplets have been introduced as a promising contrast agent for photoacoustic and ultrasound imaging that not only provide significantly enhanced contrast but also have potential as photoacoustic theranostic molecular probes incorporated with targeting molecules and therapeutics. For further understanding the dynamics of optical droplet vaporization process, an innovative, methodical analysis by concurrent acoustical and ultrafast optical recordings, comparing with a theoretical model has been employed. In addition, the repeatability of the droplet vaporization-recondensation process, which enables continuous photoacoustic imaging has been studied through the same approach. Further understanding the underlying physics of the optical droplet vaporization and associated dynamics may guide the optimal design of the droplets. Some innovative approaches in preclinical studies have been recently demonstrated, including sono-photoacoustic imaging, dual-modality of photoacoustic and ultrasound imaging, and super-resolution photoacoustic imaging. In this review, current development of optically triggered phase-transition droplets and understanding on the vaporization dynamics, their applications are introduced and future directions are discussed.

Comparison on QRS duration and cardiac function during Multi-site pacing in the right ventricular / 中国医师进修杂志

Objective To assess the effect of QRS duration (QRSd) and cardiac function during right ventricular apex(RVA) pacing,right ventricular outflow tract (RVOT) pacing and right ventricular bifocal (RV-Bi) pacing. Methods Eight patients underwent RVA pacing,RVOT pacing and RV-Bi pacing during pacemaker implantation operation.The ejection fraction (EF),stroke index (SV),cardiac output(CO),QRS QRSd,QRS axis (QRSa) were measured after each pacing at the same pacing frequency. Results Compared with RVA pacing,the EF,SV and CO increased during RVOT pacing and RV-Bi pacing.The cardiac function of RV-Bi pacing was significantly increased (P