Experimental study on hydrodynamic behaviors of high-speed gas jets in still water

The present paper describes experimental investigation on the flow pattern and hydrodynamic effect of underwater gas jets from supersonic and sonic nozzles operated in correct- and imperfect expansion conditions. The flow visualizations show that jetting is the flow regime for the submerged gas injection at a high speed in the parameter range under consideration. The obtained results indicate that high-speed gas jets in still water induce large pressure pulsations upstream of the nozzle exit and the presence of shock-cell structure in the over- and under-expanded jets leads to an increase in the intensity of the jet-induced hydrodynamic pressure.

Efficacy and safety of transvaginal mesh repair in a cohort with a minimum of 10-year follow-up

Although transvaginal mesh(TVM)repair is no longer used in some countries,long-term outcomes after TVM surgery are of great importance globally.However,reports with follow-up>10 years are limited.Thus,this study aimed to report outcomes in a prospective cohort with at least 10 years of follow-up.Women with stageⅢ–Ⅳsymptomatic prolapse were approached consecutively from 2008 to 2013 at one tertiary hospital.The main outcome measure was symptomatic failure.Secondary outcomes included anatomic failure,recurrence,patient satisfaction,complications,and reoperation.The Kaplan-Meier curve was used to estimate the cumulative failure rate.Of the 121 patients enrolled in the study,103(85.1%)completed a median follow-up of 11 years.The estimated probability rates of symptomatic and anatomic failure were 17.6%and 8.8%in 11 years,respectively.The estimated incidence of symptomatic failure increased by 8.2%between 5 and 11 years;however,the corresponding rate for anatomic failure was 3.7%.The most common complication was vaginal mesh exposure,and its estimated probability increased from 19.3%to 28.4%from 5 to 11 years,respectively.Office trimming resolved 80.0%of vaginal exposures.These patients did not report decreased overall satisfaction.Patients with vaginal mesh exposure requiring>3 office procedures or mesh removal in the operating room(5.8%by 11 years)had lower satisfaction rates(P<0.01)and were defined as having severe mesh exposure.The rates of postoperative pain,reoperation,and Patient Global Impression of Improvement≥2 were 2.5%,3.3%,and 94.2%,respectively.The results of this study implied that TVM treatment gradually increased the symptomatic failure rate but provided durable anatomical support of the vaginal wall.Vaginal mesh exposure was common in women who were largely not sexually active;however,80%of the cases could be managed in the outpatient clinic,which did not affect patient satisfaction.

激波与亚毫米液滴相互作用的二维和三维数值模拟研究

为了研究激波与亚毫米液滴相互作用过程,基于现有的实验结果,利用Fluent平台,采用VOF (Volume of Fluid)多相流模型和k-ε湍流模型,通过二维数值模拟分析了不同韦伯数(We)对亚毫米液滴变形演化过程的影响规律,通过三维数值模拟揭示了亚毫米液滴爆炸式破碎机理。结果表明,韦伯数对液滴变形有促进作用,韦伯数越大,液滴在压缩变形阶段所需要的时间越短;在气动力不变的条件下,相同液滴直径条件下,马赫数越大,液滴所受的气动力越大,液滴质心位移的无量纲加速度越大,低韦伯数下液滴的横向展开速率随韦伯数增大而减小,而高韦伯数下液滴的横向展开速率随韦伯数增大而增大。数值模拟结果与对比实验结果相近,有效阐明了韦伯数对亚毫米液滴变形的作用。

Burch colposuspension for stress urinary incontinence: a 14-year prospective follow-up

We aimed to evaluate the long-term effectiveness and safety of Burch colposuspension(BC) for stress urinary incontinence(SUI). In this prospective cohort study, 84 patients with SUI undergoing BC were enrolled from February 2004 to January 2010.Data on long-term subjective success and postoperative complications were collected at clinic visits and by telephone follow-up.During a mean follow-up period of 14.2 years, 68%(57/84) patients completed the follow-up. A total of 68.4% of patients(39/57) reported absence of SUI symptoms, 73.6%(42/57) were subjectively satisfied according to the Patient Global Impression of Improvement, and 68.4%(39/57) reported subjective success regarding urinary symptoms via the Urinary Distress Inventory Short Form. However, 28.1%(16/57) suffered at least one long-term postoperative complication and incident. Specifically, 1 in25(4.0%) sexually active patients reported dyspareunia, 3 patients(5.3%) had de novo overactive bladder, and 6 patients(10.5%)reported voiding dysfunction. Four patients(7.0%) reported new onset prolapse symptoms, and 3 patients(5.3%) underwent secondary urinary incontinence surgery. Our study indicated that Burch colposuspension is an effective procedure for SUI, and the cure effect was largely maintained for the 14-year follow-up period, with relatively low complication rates. BC should be considered a surgical option for SUI.