Shock waves in the nozzle during supersonic separation under different conditions can disrupt the flow field’s thermodynamic equilibrium.While it contributes to the recovery of pressure energy,it also leads to the di...Shock waves in the nozzle during supersonic separation under different conditions can disrupt the flow field’s thermodynamic equilibrium.While it contributes to the recovery of pressure energy,it also leads to the dissipation of mechanical energy.This study aimed to investigate the effects of changes in back pressure on the shock wave position and its subsequent impact on the refrigeration performance of nozzles.A mathematical model for the supersonic gas in a nozzle was established and evaluated via experiments.The results show that when the back pressure is less than 0.2 MPa,no shock wave is generated in the nozzle,and high refrigeration and liquefaction efficiency can be ensured while effective pressure recovery is achieved.When the back pressure(pb)is increased from 0.3 to 0.6 MPa,the refrigeration efficiency of the nozzle decreases,and the shock wave position(x shock)is advanced from 157 to 118 mm.The maximum Mach number(Ma)that can be reached by the fluid in the nozzle is reduced from 1.97 to 1.27.When the back pressure is increased from 0.2 to 0.6 MPa,the minimum temperature is increased by 55.18 K.When the back pressure is greater than 0.3 MPa,the Mach number upstream of the shock wave is reduced from 1.97 to 1.27,the shock wave intensity is weakened,and the thickness of the boundary layer separation caused by the shock wave is also decreased accordingly.Therefore,to ensure refrigeration efficiency,measures should be taken to control the back pressure within a reasonable range.展开更多
Objective We aimed to compare the clinical outcomes of intravenous urography-assisted fluoroscopy-guided shockwave lithotripsy for radiolucent ureteral stones and standard shockwave lithotripsy for radiopaque ureteral...Objective We aimed to compare the clinical outcomes of intravenous urography-assisted fluoroscopy-guided shockwave lithotripsy for radiolucent ureteral stones and standard shockwave lithotripsy for radiopaque ureteral stones.Methods We retrospectively reviewed 734 patients with ureteral stones treated by fluoroscopy-guided shockwave lithotripsy between March 2014 and March 2021.The primary outcome was a stone-free rate with one session within 30 days,defined as no residual stones without auxiliary treatment.The multivariate analysis was used to examine whether the intravenous urography use predicted treatment success.Furthermore,we compared the outcomes using propensity score matching.Results Ninety-eight patients underwent the intravenous urography use protocol(Group I),and the remaining 636 patients underwent the non-intravenous urography protocol(Group N).Stone-free rates with one session within 30 days were 38%and 32%in groups I and N,respectively(p=0.3).No statistical differences were observed in the conversion rate to ureteroscopy(p=0.3)or complication rate(p=0.7)between Group I and Group N.One patient who developed skin redness was considered a complication of the contrast medium.Propensity score matching examined 88 matched pairs.Treatment success was obtained in 31(35%)patients in Group I and 33(38%)patients in Group N(p=0.9)within 30 days with one session.Conclusion Radiolucent stones can be safely and effectively treated by shockwave lithotripsy with intravenous urography.展开更多
Low intensity shockwave (LiSW) treatment is known to improve revascularization. The method has been evaluated and is used to treat vasculogenic erectile dysfunction (ED). The present study aimed to demonstrate the eff...Low intensity shockwave (LiSW) treatment is known to improve revascularization. The method has been evaluated and is used to treat vasculogenic erectile dysfunction (ED). The present study aimed to demonstrate the efficacy of a linear focused piezoelectric shockwave device (Richard Wolf/ELvationPiezowave<sup>2</sup>) to treat patients with vasculogenic ED using a novel linear shockwave tissue coverage LSTC-ED<sup><sup>®</sup> </sup>technique. A total of 75 patients were treated using the Piezowave<sup>2</sup> device and the LSTC-ED<sup><sup>®</sup></sup> technique. Patients’ erectile function was evaluated using the modified IIEF-5 (International Index of Erectile Function) scale at the beginning of treatment and at 1 month post treatment;patients were additionally questioned using our own Treatment Satisfaction Questionnaire (TSQ). The study also included a group of 50 patients treated by placebo;the outcomes of both groups were compared. The average IIEF-5 score of patients in the treatment group increased from 14.4 at baseline to 18.6 at 1 month post treatment. According to the IIEF-5 scale, treatment was successful in 81.33% of patients (61/75). According to the Treatment Satisfaction Questionnaire (answers 1 to 3 of the TSQ), treatment was successful in 77.3% of patients (58/75). In the placebo group of 50 patients only 5 patients showed an improvement based on IIEF score, and 8 reported an improvement based on their answers to the TSQ. No significant adverse effects were observed during treatment or in the follow-up period. The Piezowave<sup>2</sup> device and the LSTC-ED<sup><sup>®</sup> </sup>technique proved to be suitable and effective to treat erectile dysfunction.展开更多
Low-intensity extracorporeal shockwave therapy(LiESWT)represents a promising treatment for patients with erectile dysfunction(ED).We investigated the efficacy of LiESWT combined with tadalafil 5 mg once daily in men w...Low-intensity extracorporeal shockwave therapy(LiESWT)represents a promising treatment for patients with erectile dysfunction(ED).We investigated the efficacy of LiESWT combined with tadalafil 5 mg once daily in men with type 2 diabetes mellitus(T2DM)and ED and compared LiESWT protocols administering different number of shockwaves.We performed a retrospective matched-pair comparison using data from a prospectively maintained database.Seventy-eight patients who received tadalafil 5 mg once dai7ly for 12 weeks+LiESWT performed with an electrohydraulic source for 3 weeks(Group A)were matched 1:1 to patients who received tadalafil 5 mg once daily alone for 12 weeks(Group B).A subgroup analysis was performed according to the number of shockwaves delivered during each session(1500,1800,and 2400 in subgroup A1,A2,and A3,respectively).The mean International Index of Erectile Function-5(IIEF-5)score variations with respect to baseline recorded at 4,12,and 24 weeks after the end of the treatment were investigated as treatment outcomes.The mean IIEF-5 scores significantly improved in all groups and subgroups at 4-week follow-up without intergroup differences.At 12-and 24-week follow-up,the mean IIEF-5 improvement was significantly higher among patients in the A3 subgroup(+5.0±2.1[P<0.001]and+4.7±2.3[P<0.001],respectively).The combined approach with tadalafil 5 mg once daily and LiESWT with a protocol involving 2400 shockwaves provides significant advantages in terms of IIEF-5 improvement and durability compared to tadalafil 5 mg once daily alone in patients with T2DM and ED.展开更多
基金supported by the National Science and Technology Major Project of China(2025ZD1406703)the Open Fund of Key Laboratory of Oil&Gas Equipment,Ministry of Education(Southwest Petroleum University)(Grant No.OGE20230206).
文摘Shock waves in the nozzle during supersonic separation under different conditions can disrupt the flow field’s thermodynamic equilibrium.While it contributes to the recovery of pressure energy,it also leads to the dissipation of mechanical energy.This study aimed to investigate the effects of changes in back pressure on the shock wave position and its subsequent impact on the refrigeration performance of nozzles.A mathematical model for the supersonic gas in a nozzle was established and evaluated via experiments.The results show that when the back pressure is less than 0.2 MPa,no shock wave is generated in the nozzle,and high refrigeration and liquefaction efficiency can be ensured while effective pressure recovery is achieved.When the back pressure(pb)is increased from 0.3 to 0.6 MPa,the refrigeration efficiency of the nozzle decreases,and the shock wave position(x shock)is advanced from 157 to 118 mm.The maximum Mach number(Ma)that can be reached by the fluid in the nozzle is reduced from 1.97 to 1.27.When the back pressure is increased from 0.2 to 0.6 MPa,the minimum temperature is increased by 55.18 K.When the back pressure is greater than 0.3 MPa,the Mach number upstream of the shock wave is reduced from 1.97 to 1.27,the shock wave intensity is weakened,and the thickness of the boundary layer separation caused by the shock wave is also decreased accordingly.Therefore,to ensure refrigeration efficiency,measures should be taken to control the back pressure within a reasonable range.
文摘Objective We aimed to compare the clinical outcomes of intravenous urography-assisted fluoroscopy-guided shockwave lithotripsy for radiolucent ureteral stones and standard shockwave lithotripsy for radiopaque ureteral stones.Methods We retrospectively reviewed 734 patients with ureteral stones treated by fluoroscopy-guided shockwave lithotripsy between March 2014 and March 2021.The primary outcome was a stone-free rate with one session within 30 days,defined as no residual stones without auxiliary treatment.The multivariate analysis was used to examine whether the intravenous urography use predicted treatment success.Furthermore,we compared the outcomes using propensity score matching.Results Ninety-eight patients underwent the intravenous urography use protocol(Group I),and the remaining 636 patients underwent the non-intravenous urography protocol(Group N).Stone-free rates with one session within 30 days were 38%and 32%in groups I and N,respectively(p=0.3).No statistical differences were observed in the conversion rate to ureteroscopy(p=0.3)or complication rate(p=0.7)between Group I and Group N.One patient who developed skin redness was considered a complication of the contrast medium.Propensity score matching examined 88 matched pairs.Treatment success was obtained in 31(35%)patients in Group I and 33(38%)patients in Group N(p=0.9)within 30 days with one session.Conclusion Radiolucent stones can be safely and effectively treated by shockwave lithotripsy with intravenous urography.
文摘Low intensity shockwave (LiSW) treatment is known to improve revascularization. The method has been evaluated and is used to treat vasculogenic erectile dysfunction (ED). The present study aimed to demonstrate the efficacy of a linear focused piezoelectric shockwave device (Richard Wolf/ELvationPiezowave<sup>2</sup>) to treat patients with vasculogenic ED using a novel linear shockwave tissue coverage LSTC-ED<sup><sup>®</sup> </sup>technique. A total of 75 patients were treated using the Piezowave<sup>2</sup> device and the LSTC-ED<sup><sup>®</sup></sup> technique. Patients’ erectile function was evaluated using the modified IIEF-5 (International Index of Erectile Function) scale at the beginning of treatment and at 1 month post treatment;patients were additionally questioned using our own Treatment Satisfaction Questionnaire (TSQ). The study also included a group of 50 patients treated by placebo;the outcomes of both groups were compared. The average IIEF-5 score of patients in the treatment group increased from 14.4 at baseline to 18.6 at 1 month post treatment. According to the IIEF-5 scale, treatment was successful in 81.33% of patients (61/75). According to the Treatment Satisfaction Questionnaire (answers 1 to 3 of the TSQ), treatment was successful in 77.3% of patients (58/75). In the placebo group of 50 patients only 5 patients showed an improvement based on IIEF score, and 8 reported an improvement based on their answers to the TSQ. No significant adverse effects were observed during treatment or in the follow-up period. The Piezowave<sup>2</sup> device and the LSTC-ED<sup><sup>®</sup> </sup>technique proved to be suitable and effective to treat erectile dysfunction.
文摘Low-intensity extracorporeal shockwave therapy(LiESWT)represents a promising treatment for patients with erectile dysfunction(ED).We investigated the efficacy of LiESWT combined with tadalafil 5 mg once daily in men with type 2 diabetes mellitus(T2DM)and ED and compared LiESWT protocols administering different number of shockwaves.We performed a retrospective matched-pair comparison using data from a prospectively maintained database.Seventy-eight patients who received tadalafil 5 mg once dai7ly for 12 weeks+LiESWT performed with an electrohydraulic source for 3 weeks(Group A)were matched 1:1 to patients who received tadalafil 5 mg once daily alone for 12 weeks(Group B).A subgroup analysis was performed according to the number of shockwaves delivered during each session(1500,1800,and 2400 in subgroup A1,A2,and A3,respectively).The mean International Index of Erectile Function-5(IIEF-5)score variations with respect to baseline recorded at 4,12,and 24 weeks after the end of the treatment were investigated as treatment outcomes.The mean IIEF-5 scores significantly improved in all groups and subgroups at 4-week follow-up without intergroup differences.At 12-and 24-week follow-up,the mean IIEF-5 improvement was significantly higher among patients in the A3 subgroup(+5.0±2.1[P<0.001]and+4.7±2.3[P<0.001],respectively).The combined approach with tadalafil 5 mg once daily and LiESWT with a protocol involving 2400 shockwaves provides significant advantages in terms of IIEF-5 improvement and durability compared to tadalafil 5 mg once daily alone in patients with T2DM and ED.
