In order to improve the performance of plaster molds for investment casting,a diverse content of glass fiber and polypropylene(PP)fiber was incorporated into the slurry for the preparation of a fiber-reinforced mold.T...In order to improve the performance of plaster molds for investment casting,a diverse content of glass fiber and polypropylene(PP)fiber was incorporated into the slurry for the preparation of a fiber-reinforced mold.The green and fired bending strengths,thermal expansion properties,permeability,and thermal shock resistance of the mold were examined,and the scanning electron microscope(SEM)with energy dispersive spectrometer(EDS)was applied for the observation of fracture morphology.With appropriate content,the introduction of glass fiber was proved to increase the green bending strength and fired bending strength,restrain the thermal expansion and improve the thermal shock resistance of the mold,while the polypropylene fiber added was able to raise the green bending strength and the permeability,reduce the thermal expansion and heighten the thermal shock resistance as well,though the fired bending strength would be weakened slightly.Evenly distributed fibers were capable of enhancing the mechanical properties of the matrix,but agglomerations and bundles of fibers resulting from excessive addition had a negative impact.Meanwhile,it was also manifested that micropores left by ablative polypropylene fibers could improve the permeability and reduce the thermal expansion of the mold,and the fired bending strength would be decreased slightly by the deterioration of continuous structure.Three different ratios of hybrid fiber were employed in plaster molds,which can meet altered requirement of castings.The samples modified with hybrid fiber possessed lower thermal deformation,higher air permeability,and better resistance of thermal shock,while the mechanical strength was equal to the fiber free sample or slightly increased.展开更多
目的:探究“针-药-模”结合治疗粉刺病肺胃热蕴证的临床效果。方法:收集2020年10月—2022年9月上海市嘉定区中医医院皮肤科门诊收治的粉刺病肺胃热蕴证患者150例,根据随机数字表法将其分为针-药-模治疗组(桑枇消痤颗粒+毫火针+石膏倒模...目的:探究“针-药-模”结合治疗粉刺病肺胃热蕴证的临床效果。方法:收集2020年10月—2022年9月上海市嘉定区中医医院皮肤科门诊收治的粉刺病肺胃热蕴证患者150例,根据随机数字表法将其分为针-药-模治疗组(桑枇消痤颗粒+毫火针+石膏倒模)、针-药对照组(桑枇消痤颗粒+毫火针)、药-模对照组(桑枇消痤颗粒+石膏倒模),每组50例,均每周治疗1次,持续治疗4周。观察3组患者的临床疗效,比较3组治疗前后皮疹情况及生活质量[皮肤病生活质量指数量表(dermatology quality of life index,DLQI)],统计不良反应发生情况与复发率。结果:治疗4周后,针-药-模治疗组临床有效率高于针-药对照组、药-模对照组,差异有统计学意义;针-药对照组与药-模对照组比较,差异无统计学意义。3组患者皮疹情况评分、DLQI评分与治疗前比较均降低,且针-药-模治疗组低于针-药对照组及药-模对照组,差异有统计学意义;针-药对照组与药-模对照组比较,差异无统计学意义。治疗期间,3组患者不良反应发生情况比较,差异无统计学意义;结束治疗后2个月,针-药-模治疗组复发率低于针-药对照组、药-模对照组,差异有统计学意义;针-药对照组与药-模对照组比较,差异无统计学意义。结论:与“药-模”及“针-药”治疗相比,“针-药-模”相结合的综合治疗方法在粉刺病肺胃热蕴证的治疗中临床疗效更为显著,有效改善患者皮疹情况,提高生活质量,减少复发,安全性可靠。展开更多
AIM To determine if complete, split casts and backslabs [plaster of Paris(POP) and fiberglass] generate different intracast pressures and pain. METHODS Increased swelling within casts was modeled by a closed water sys...AIM To determine if complete, split casts and backslabs [plaster of Paris(POP) and fiberglass] generate different intracast pressures and pain. METHODS Increased swelling within casts was modeled by a closed water system attached to an expandable bag placed directly under different types of casts applied to a healthy lower limb. Complete fiberglass and POP casts, split casts and backslabs were applied. Twenty-five milliliter aliquots of saline were injected into the system and the generated intracast pressures were measured using a sphygmomanometer. The subject was blinded to the pressure scores to avoid bias. All casts were applied to the same right limb on the same subject to avoid the effects of variations in anatomy or physiology on intracast pressures. Pain levels were evaluated using the Visual Analogue Score after each sequential saline injection. Each type of cast was reapplied four times and the measurements were repeated on four separate occasions. Sample sizes were determined by a pre-study 90% power calculation to detect a 20% difference in intracast pressures between cast groups. RESULTS A significant difference between the various types of casts was noted when the saline volume was greater than 100 mL(P = 0.009). The greatest intracast pressure was generated by complete fiberglass casts, which were significantly higher than complete POP casts or backslabs(P = 0.018 and P = 0.008 respectively) at intracast saline volumes of 100 mL and higher. Backslabs produced a significantly lower intracast pressure compared to complete POP only once the saline volume within casts exceeded 225 mL(P = 0.009). Intracast pressures were significantly lower in split casts(P = 0.003). Split POP and fiberglass casts produced the lowest intracast pressures, even compared to backslabs(P = 0.009). Complete fiberglass casts generated the highest pain levels at manometer pressures of 75 mm Hg and greater(P = 0.001). Split fiberglass casts had significantly reduced pain levels(P = 0.001). In contrast, a split complete POP cast did not produce significantly reduced pain levels at pressures between 25-150 mmH g. There was no difference in pain generated by complete POP and backslabs at manometer pressures of 200 mm Hg and lower. CONCLUSION Fibreglass casts generate significantly higher intracast pressures and pain than POP casts. Split casts cause lower intracast pressures regardless of material, than complete casts and backslabs.展开更多
文摘In order to improve the performance of plaster molds for investment casting,a diverse content of glass fiber and polypropylene(PP)fiber was incorporated into the slurry for the preparation of a fiber-reinforced mold.The green and fired bending strengths,thermal expansion properties,permeability,and thermal shock resistance of the mold were examined,and the scanning electron microscope(SEM)with energy dispersive spectrometer(EDS)was applied for the observation of fracture morphology.With appropriate content,the introduction of glass fiber was proved to increase the green bending strength and fired bending strength,restrain the thermal expansion and improve the thermal shock resistance of the mold,while the polypropylene fiber added was able to raise the green bending strength and the permeability,reduce the thermal expansion and heighten the thermal shock resistance as well,though the fired bending strength would be weakened slightly.Evenly distributed fibers were capable of enhancing the mechanical properties of the matrix,but agglomerations and bundles of fibers resulting from excessive addition had a negative impact.Meanwhile,it was also manifested that micropores left by ablative polypropylene fibers could improve the permeability and reduce the thermal expansion of the mold,and the fired bending strength would be decreased slightly by the deterioration of continuous structure.Three different ratios of hybrid fiber were employed in plaster molds,which can meet altered requirement of castings.The samples modified with hybrid fiber possessed lower thermal deformation,higher air permeability,and better resistance of thermal shock,while the mechanical strength was equal to the fiber free sample or slightly increased.
文摘目的:探究“针-药-模”结合治疗粉刺病肺胃热蕴证的临床效果。方法:收集2020年10月—2022年9月上海市嘉定区中医医院皮肤科门诊收治的粉刺病肺胃热蕴证患者150例,根据随机数字表法将其分为针-药-模治疗组(桑枇消痤颗粒+毫火针+石膏倒模)、针-药对照组(桑枇消痤颗粒+毫火针)、药-模对照组(桑枇消痤颗粒+石膏倒模),每组50例,均每周治疗1次,持续治疗4周。观察3组患者的临床疗效,比较3组治疗前后皮疹情况及生活质量[皮肤病生活质量指数量表(dermatology quality of life index,DLQI)],统计不良反应发生情况与复发率。结果:治疗4周后,针-药-模治疗组临床有效率高于针-药对照组、药-模对照组,差异有统计学意义;针-药对照组与药-模对照组比较,差异无统计学意义。3组患者皮疹情况评分、DLQI评分与治疗前比较均降低,且针-药-模治疗组低于针-药对照组及药-模对照组,差异有统计学意义;针-药对照组与药-模对照组比较,差异无统计学意义。治疗期间,3组患者不良反应发生情况比较,差异无统计学意义;结束治疗后2个月,针-药-模治疗组复发率低于针-药对照组、药-模对照组,差异有统计学意义;针-药对照组与药-模对照组比较,差异无统计学意义。结论:与“药-模”及“针-药”治疗相比,“针-药-模”相结合的综合治疗方法在粉刺病肺胃热蕴证的治疗中临床疗效更为显著,有效改善患者皮疹情况,提高生活质量,减少复发,安全性可靠。
文摘AIM To determine if complete, split casts and backslabs [plaster of Paris(POP) and fiberglass] generate different intracast pressures and pain. METHODS Increased swelling within casts was modeled by a closed water system attached to an expandable bag placed directly under different types of casts applied to a healthy lower limb. Complete fiberglass and POP casts, split casts and backslabs were applied. Twenty-five milliliter aliquots of saline were injected into the system and the generated intracast pressures were measured using a sphygmomanometer. The subject was blinded to the pressure scores to avoid bias. All casts were applied to the same right limb on the same subject to avoid the effects of variations in anatomy or physiology on intracast pressures. Pain levels were evaluated using the Visual Analogue Score after each sequential saline injection. Each type of cast was reapplied four times and the measurements were repeated on four separate occasions. Sample sizes were determined by a pre-study 90% power calculation to detect a 20% difference in intracast pressures between cast groups. RESULTS A significant difference between the various types of casts was noted when the saline volume was greater than 100 mL(P = 0.009). The greatest intracast pressure was generated by complete fiberglass casts, which were significantly higher than complete POP casts or backslabs(P = 0.018 and P = 0.008 respectively) at intracast saline volumes of 100 mL and higher. Backslabs produced a significantly lower intracast pressure compared to complete POP only once the saline volume within casts exceeded 225 mL(P = 0.009). Intracast pressures were significantly lower in split casts(P = 0.003). Split POP and fiberglass casts produced the lowest intracast pressures, even compared to backslabs(P = 0.009). Complete fiberglass casts generated the highest pain levels at manometer pressures of 75 mm Hg and greater(P = 0.001). Split fiberglass casts had significantly reduced pain levels(P = 0.001). In contrast, a split complete POP cast did not produce significantly reduced pain levels at pressures between 25-150 mmH g. There was no difference in pain generated by complete POP and backslabs at manometer pressures of 200 mm Hg and lower. CONCLUSION Fibreglass casts generate significantly higher intracast pressures and pain than POP casts. Split casts cause lower intracast pressures regardless of material, than complete casts and backslabs.
