通过对超临界流体快速膨胀法(rapid expansion of supercritical solution,RESS)流动过程的简化与分析,建立了喷嘴节流流动过程模型,一维定常过程数学模型的描述包括了锥体入口段、直管膨胀段和到达马赫盘位置的出口超音速膨胀段.给出...通过对超临界流体快速膨胀法(rapid expansion of supercritical solution,RESS)流动过程的简化与分析,建立了喷嘴节流流动过程模型,一维定常过程数学模型的描述包括了锥体入口段、直管膨胀段和到达马赫盘位置的出口超音速膨胀段.给出了模型中的主要计算参数来源以及解算过程的基本思路.据此模型,在给定初值条件下,对各个阶段的流动状态进行模拟计算,得到了流体的密度、压力、温度、速度等参数沿喷嘴轴向的变化数据,并进行了初步验证.该模型和模拟过程能够为实现制备均一微细颗粒的实际操作条件和优化过程参数奠定基础.展开更多
采用超临界流体R ESS法对超细黑索今(RD X)进行了包覆,研究了不同系统温度、溶液浓度、系统压力对包覆后超细RD X造型粉效果的影响,并对其进行撞击感度测试。结果表明,系统温度45℃以上,造型粉颗粒之间氟橡胶粘结在一起,分散性较差;氟...采用超临界流体R ESS法对超细黑索今(RD X)进行了包覆,研究了不同系统温度、溶液浓度、系统压力对包覆后超细RD X造型粉效果的影响,并对其进行撞击感度测试。结果表明,系统温度45℃以上,造型粉颗粒之间氟橡胶粘结在一起,分散性较差;氟橡胶浓度0.4 g/m L以上,其造型粉颗粒尺寸增大;系统压力降低到12 M P a以下,颗粒表面未完全被氟橡胶包覆,且分散性也较差。当系统温度40℃、氟橡胶浓度0.3 g/m L、系统压力14 M P a、通气时间20 m in条件下,包覆效果最好。包覆后样品撞击感度特性落高比超细RD X(25.2 cm)提高了9.48 cm。展开更多
Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon d...Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).展开更多
The inherent characteristics in the rapid expansion process of supercritical fluid solution were analyzed. The temperature change resulted from the throttling expansion of the supercritical fluid, and the strong turbu...The inherent characteristics in the rapid expansion process of supercritical fluid solution were analyzed. The temperature change resulted from the throttling expansion of the supercritical fluid, and the strong turbulence in the expansion flow resulted from the quick change of the fluid pressure were experimentally measured. It was proposed that the temperature and turbulence in the expansion flow affect the particle nucleation, growth or coating process significantly.展开更多
目的:探究高血压脑出血患者入院后颅内血肿早期进展的相关危险因素。方法:收集2017年1月至2022年12月广州市中西医结合医院收治的高血压脑出血患者的临床资料。将其中入院后24小时内出现血肿增加情况的患者作为加重组,将未增加的患者作...目的:探究高血压脑出血患者入院后颅内血肿早期进展的相关危险因素。方法:收集2017年1月至2022年12月广州市中西医结合医院收治的高血压脑出血患者的临床资料。将其中入院后24小时内出现血肿增加情况的患者作为加重组,将未增加的患者作为对照组。收集两组患者的性别、年龄、入院格拉斯哥昏迷量表(Glasgow Coma Score,GCS)评分、发病到入院时长、是否合并高血压和糖尿病、血压波动值、入院时血肿量等资料,分析影响血肿早期增加的危险因素。结果:单因素分析显示,两组患者的年龄、性别、GCS评分、发病至入院时间和入院时血肿量相比,无统计学差异(P>0.05)。两组患者的血压波幅、合并高血压和糖尿病的比例相比,有统计学差异(P<0.05)。多因素逻辑回归分析发现,血压波幅大、发病至入院时间短、合并高血压和糖尿病是影响早期血肿进展的独立危险因素(OR=1.408,P<0.001;OR=2.104,P=0.046;OR=1.495,P=0.037;OR=3.294,P=0.002)。结论:高血压脑出血患者的血压波幅大、发病至入院时间短、合并高血压和糖尿病等情况是影响其颅内血肿早期进展的危险因素。展开更多
文摘通过对超临界流体快速膨胀法(rapid expansion of supercritical solution,RESS)流动过程的简化与分析,建立了喷嘴节流流动过程模型,一维定常过程数学模型的描述包括了锥体入口段、直管膨胀段和到达马赫盘位置的出口超音速膨胀段.给出了模型中的主要计算参数来源以及解算过程的基本思路.据此模型,在给定初值条件下,对各个阶段的流动状态进行模拟计算,得到了流体的密度、压力、温度、速度等参数沿喷嘴轴向的变化数据,并进行了初步验证.该模型和模拟过程能够为实现制备均一微细颗粒的实际操作条件和优化过程参数奠定基础.
文摘采用超临界流体R ESS法对超细黑索今(RD X)进行了包覆,研究了不同系统温度、溶液浓度、系统压力对包覆后超细RD X造型粉效果的影响,并对其进行撞击感度测试。结果表明,系统温度45℃以上,造型粉颗粒之间氟橡胶粘结在一起,分散性较差;氟橡胶浓度0.4 g/m L以上,其造型粉颗粒尺寸增大;系统压力降低到12 M P a以下,颗粒表面未完全被氟橡胶包覆,且分散性也较差。当系统温度40℃、氟橡胶浓度0.3 g/m L、系统压力14 M P a、通气时间20 m in条件下,包覆效果最好。包覆后样品撞击感度特性落高比超细RD X(25.2 cm)提高了9.48 cm。
文摘Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).
基金Supported by the National Natural Science Foundation of China(No.29906004)
文摘The inherent characteristics in the rapid expansion process of supercritical fluid solution were analyzed. The temperature change resulted from the throttling expansion of the supercritical fluid, and the strong turbulence in the expansion flow resulted from the quick change of the fluid pressure were experimentally measured. It was proposed that the temperature and turbulence in the expansion flow affect the particle nucleation, growth or coating process significantly.
文摘目的:探究高血压脑出血患者入院后颅内血肿早期进展的相关危险因素。方法:收集2017年1月至2022年12月广州市中西医结合医院收治的高血压脑出血患者的临床资料。将其中入院后24小时内出现血肿增加情况的患者作为加重组,将未增加的患者作为对照组。收集两组患者的性别、年龄、入院格拉斯哥昏迷量表(Glasgow Coma Score,GCS)评分、发病到入院时长、是否合并高血压和糖尿病、血压波动值、入院时血肿量等资料,分析影响血肿早期增加的危险因素。结果:单因素分析显示,两组患者的年龄、性别、GCS评分、发病至入院时间和入院时血肿量相比,无统计学差异(P>0.05)。两组患者的血压波幅、合并高血压和糖尿病的比例相比,有统计学差异(P<0.05)。多因素逻辑回归分析发现,血压波幅大、发病至入院时间短、合并高血压和糖尿病是影响早期血肿进展的独立危险因素(OR=1.408,P<0.001;OR=2.104,P=0.046;OR=1.495,P=0.037;OR=3.294,P=0.002)。结论:高血压脑出血患者的血压波幅大、发病至入院时间短、合并高血压和糖尿病等情况是影响其颅内血肿早期进展的危险因素。
