OBJECTIVE:To establish the method for determining 10 residual organic solvents in norvancomycin hydrochloride raw material. METHODS:Headspace gas chromatography was performed on the column of nitro modified polyethylene terephthal-ate glycol as stationary phase capillary column;the oven temperature program started at 40 ℃ for 3 min and increased at a rate of 8 ℃/min up to 150 ℃ for 10 min;the temperature was 200 ℃ with carrier gas of high-purity nitrogen gas,the constant flow rate was 5 ml/min with split ratio of 15∶1;the headspace vial equilibrium temperature was 85 ℃ with equilibrium time of 40 min,and the volume was 1 ml. RESULTS:The concentration of n-pentane,acetone,ethanol,benzene,acrylonitrile,toluene,xylene,chlo-robenzene,styrene,divinylbenzene had good linear relationship with its peak area values(r=0.995 7-0.999 9);the RSDs of preci-sion,repeatability tests was ≤6.6%;average recovery was in the range of 94.3%-106.6%(RSD=0.5%-4.5%,n=9). CONCLU-SIONS:The method is fast,sensitive and accurate,and can be used for the determination of residual organic solvents in norvanco-mycin hydrochloride raw material.

OBJECTIVETo evaluate the reliability of diagnostic ultrasound-based temperature and elasticity imaging during radiofrequency ablation (RFA) through ex vivo experiments.

METHODSProcine liver samples (n=7) were employed for RFA experiments with exposures of different power intensities (10 and 50w). The RFA process was monitored by a diagnostic ultrasound imager and the information were postoperatively captured for further temperature and elasticity image analysis. Infrared thermometry was concurrently applied to provide temperature change calibration during the RFA process.

RESULTSResults from this study demonstrated that temperature imaging was valid under 10 W RF exposure (r=0.95), but the ablation zone was no longer consistent with the reference infrared temperature distribution under high RF exposures. The elasticity change could well reflect the ablation zone under a 50 W exposure, whereas under low exposures, the thermal lesion could not be well detected due to the limited range of temperature elevation and incomplete tissue necrosis.

CONCLUSIONDiagnostic ultrasound-based temperature and elastography is valid for monitoring thr RFA process. Temperature estimation can well reflect mild-power RF ablation dynamics, whereas the elastic-change estimation can can well predict the tissue necrosis. This study provide advances toward using diagnostic ultrasound to monitor RFA or other thermal-based interventions.

Animals ; Catheter Ablation ; methods ; Elasticity Imaging Techniques ; Liver ; diagnostic imaging ; Swine ; Temperature

Objective To evaluate the reliability of diagnostic ultrasound-based temperature and elasticity imaging during radiofrequency ablation (RFA) through ex vivo experiments. Methods Procine liver samples (n=7) were employed for RFA experiments with exposures of different power intensities (10 and 50w). The RFA process was monitored by a diagnostic ultrasound imager and the information were postoperatively captured for further temperture and elasticity image analysis. Infarred themometry was concurrently applied to provide temperatuer change calibation during the RFA process. Results Results from this study demonstrated that temperature imaging was valid under 10 W RF exposure (r=0.95), but the ablation zone was no longer consistent with the reference infarred tempetuare distriubtion under high RF exposures. The elstaicity change could well reflect the ablation zone under a 50 W exposure, whereas under low exposures, the thermal lesion could not be well detected due to the limited range of temperature elevation and incomplete tissue necrosis. Conclusion Diagnostic ultrasound-based temperaure and elastogrphy is valid for monitoring thr RFA process. Temperature estimation can well reflect mild-power RF ablation dynamics, wehreas the elastic-change estimation can can well predict the tissue necrosis. This study provide advances torward using diagnostic ultrasound to monitor RFA or other thermal-based interventions.

Objective To evaluate the reliability of diagnostic ultrasound-based temperature and elasticity imaging during radiofrequency ablation (RFA) through ex vivo experiments. Methods Procine liver samples (n=7) were employed for RFA experiments with exposures of different power intensities (10 and 50w). The RFA process was monitored by a diagnostic ultrasound imager and the information were postoperatively captured for further temperture and elasticity image analysis. Infarred themometry was concurrently applied to provide temperatuer change calibation during the RFA process. Results Results from this study demonstrated that temperature imaging was valid under 10 W RF exposure (r=0.95), but the ablation zone was no longer consistent with the reference infarred tempetuare distriubtion under high RF exposures. The elstaicity change could well reflect the ablation zone under a 50 W exposure, whereas under low exposures, the thermal lesion could not be well detected due to the limited range of temperature elevation and incomplete tissue necrosis. Conclusion Diagnostic ultrasound-based temperaure and elastogrphy is valid for monitoring thr RFA process. Temperature estimation can well reflect mild-power RF ablation dynamics, wehreas the elastic-change estimation can can well predict the tissue necrosis. This study provide advances torward using diagnostic ultrasound to monitor RFA or other thermal-based interventions.