AIM:To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits.METHODS:Three ports were prepared near the third eyelid of rabbits,and the infusion port was placed a...AIM:To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits.METHODS:Three ports were prepared near the third eyelid of rabbits,and the infusion port was placed at the inferior nasal quadrant with the inserted cannula linking with a self-designed handheld rigid infusion catheter.All right eyes of rabbits underwent a modified 25-gauge vitrectomy and were subsequently filled with balanced salt solution,silicone oil,and eight-arm polyethylene glycols(8-arm PEGs)hydrogel separately for comparison.Ophthalmic examinations were performed regularly to record the changes after the surgery.RESULTS:Successful vitrectomy was achieved among 44 chinchilla rabbits.The mean operation time was 4.51±1.25min.Four eyes(9.1%)presented limited lens touch and two eyes(4.5%)showed retinal touch during surgery.Incision leakage was found in three eyes(6.8%)after surgery.There was no endophthalmitis,hemorrhage,or retinal detachment during the observation period and ophthalmic examinations after the implantation of vitreous substitutes.CONCLUSION:The modified technique of the standard vitrectomy applied in the endotamponade model in rabbits shows excellent safety and practicality.展开更多
To increase the biocompatibility of hydroxyapatite (HA), Ca10(PO4)6(OH)2, the Sr substitution of Ca into the HA structure was effected to yield Ca10-xSrx(PO4)6(OH)2(Sr-HA). For medical and dental applications, it is i...To increase the biocompatibility of hydroxyapatite (HA), Ca10(PO4)6(OH)2, the Sr substitution of Ca into the HA structure was effected to yield Ca10-xSrx(PO4)6(OH)2(Sr-HA). For medical and dental applications, it is important that Sr-HA is prepared as a thin film so that the Sr fully substitutes the Ca sites in the HA structure and does not form segregated impurities consisting of Sr compounds. If the segregated Sr forms different amounts of different impurities, the dissolution of the Sr into the living body will not be reproducible across different samples. To confirm the Sr substitution into the Ca site in the HA structure, the systematic variation in the lattice constants of the Sr-HA with Sr content was evaluated as the first step. The a- and c-axis lengths were found to exhibit a linear relationship with the Sr content for six samples with different Sr contents, indicating that the prepared Sr-HA thin films likely possessed partial Sr substitution into the Ca sites of the HA structure. This result is an important first step in the accurate evaluation of the biological effects of Sr-HA thin films.展开更多
The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, w...The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, we study the effects of fluid substitution in a physical model, which is an analogy of the three-dimensional inhomogeneous reservoir. For a weak inhomogeneous medium, gas/oil substitution results in positive anomalies in the reservoir layers, and negative anomalies below the bottom of the reservoir layers; while water/oil substitution causes only weak variations in the reservoir layers, but positive anomalies below the bottom of the reservoir layers. For the strong inhomogeneous medium, no matter what kind of fluid substitution(gas/oil or water/oil), there are significant anomalies in seismic amplitude difference attributes both in and below the reservoir layers. Therefore, for weak inhomogeneous media, such as tight sandstone or thin interbedded layers, the RMS amplitude difference attributes can be used to monitor fluid changes and predict the drilling direction; for inhomogeneous medium with karst carves or fractures, it is difficult to accurately determine the distribution of fluids with the RMS amplitude difference attributes.展开更多
基金Supported by the Project of National Key Research and Development(No.2018YFC1106103)the Health Commission of Hubei Province Scientific Research Project(No.WJ2019Q024).
文摘AIM:To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits.METHODS:Three ports were prepared near the third eyelid of rabbits,and the infusion port was placed at the inferior nasal quadrant with the inserted cannula linking with a self-designed handheld rigid infusion catheter.All right eyes of rabbits underwent a modified 25-gauge vitrectomy and were subsequently filled with balanced salt solution,silicone oil,and eight-arm polyethylene glycols(8-arm PEGs)hydrogel separately for comparison.Ophthalmic examinations were performed regularly to record the changes after the surgery.RESULTS:Successful vitrectomy was achieved among 44 chinchilla rabbits.The mean operation time was 4.51±1.25min.Four eyes(9.1%)presented limited lens touch and two eyes(4.5%)showed retinal touch during surgery.Incision leakage was found in three eyes(6.8%)after surgery.There was no endophthalmitis,hemorrhage,or retinal detachment during the observation period and ophthalmic examinations after the implantation of vitreous substitutes.CONCLUSION:The modified technique of the standard vitrectomy applied in the endotamponade model in rabbits shows excellent safety and practicality.
文摘To increase the biocompatibility of hydroxyapatite (HA), Ca10(PO4)6(OH)2, the Sr substitution of Ca into the HA structure was effected to yield Ca10-xSrx(PO4)6(OH)2(Sr-HA). For medical and dental applications, it is important that Sr-HA is prepared as a thin film so that the Sr fully substitutes the Ca sites in the HA structure and does not form segregated impurities consisting of Sr compounds. If the segregated Sr forms different amounts of different impurities, the dissolution of the Sr into the living body will not be reproducible across different samples. To confirm the Sr substitution into the Ca site in the HA structure, the systematic variation in the lattice constants of the Sr-HA with Sr content was evaluated as the first step. The a- and c-axis lengths were found to exhibit a linear relationship with the Sr content for six samples with different Sr contents, indicating that the prepared Sr-HA thin films likely possessed partial Sr substitution into the Ca sites of the HA structure. This result is an important first step in the accurate evaluation of the biological effects of Sr-HA thin films.
基金Project(2013CB228600)supported by the National Basic Research Program of China
文摘The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, we study the effects of fluid substitution in a physical model, which is an analogy of the three-dimensional inhomogeneous reservoir. For a weak inhomogeneous medium, gas/oil substitution results in positive anomalies in the reservoir layers, and negative anomalies below the bottom of the reservoir layers; while water/oil substitution causes only weak variations in the reservoir layers, but positive anomalies below the bottom of the reservoir layers. For the strong inhomogeneous medium, no matter what kind of fluid substitution(gas/oil or water/oil), there are significant anomalies in seismic amplitude difference attributes both in and below the reservoir layers. Therefore, for weak inhomogeneous media, such as tight sandstone or thin interbedded layers, the RMS amplitude difference attributes can be used to monitor fluid changes and predict the drilling direction; for inhomogeneous medium with karst carves or fractures, it is difficult to accurately determine the distribution of fluids with the RMS amplitude difference attributes.
