6,890 research outputs found
Track Momentum Discrimination Using Cluster Width in Silicon Strip Sensors for SLHC
The cluster width of a particle crossing a silicon strip (mini strip) detector can be exploited to measure its transverse momentum when the strips are parallel to the B field. This suggests the discrimination of the clusters widths to filter the majority of low momentum particles. Once performed directly on the detectors, such discrimination can be used both for low level trigger (L1) and for data reduction. This approach is discussed in the context of a first level trigger based on the Tracker for SLHC. The quality of the measurements and their discrimination capability are discussed with respect to the geometry of the sensors and to the detectors layout. Electronics issues and constraints are also reviewed
Importance of the induced recharge term in riverbank filtration: Hydrodynamics, hydrochemical, and numerical modelling investigations
While ensuring adequate drinking water supply is increasingly being a worldwide challenging need, managed aquifer recharge (MAR) schemes may provide reliable solutions in order to guarantee safe and continuous supply of water. This is particularly true in riverbank filtration (RBF) schemes. Several studies aimed at addressing the treatment capabilities of such schemes, but induced aquifer recharge hydrodynamics from surface water bodies caused by pumping wells is seldom analysed and quantified. In this study, after presenting a detailed description of the Serchio River RBF site, we used a multidisciplinary approach entailing hydrodynamics, hydrochemical, and numerical modelling methods in order to evaluate the change in recharge from the Serchio river to the aquifer due to the building of the RBF infrastructures along the Serchio river (Lucca, Italy). In this way, we estimated the increase in aquifer recharge and the ratio of bank filtrate to ambient groundwater abstracted at such RBF scheme. Results highlight that in present conditions the main source of the RBF pumping wells is the Serchio River water and that the groundwater at the Sant’Alessio plain is mainly characterized by mixing between precipitation occurring in the higher part of the plain and the River water. Based on chemical mixing, a precautionary amount of abstracted Serchio River water is estimated to be on average 13.6 Mm3 /year, which is 85% of the total amount of water abstracted in a year (~16 Mm3). RBF is a worldwide recognized MAR technique for supplying good quality and reliable amount of water. As in several cases and countries the induced recharge component is not duly acknowledged, the authors suggest including the term “induced” in the definition of this type of MAR technique (to become then IRBF). Thus, clear reference may be made to the fact that the bank filtration is not completely due to natural recharge, as in many cases of surface water/groundwater interactions, but it may be partly/almost all human-made
Repair of sphincter urethral strictures preserving urinary continence: surgical technique and outcomes
Introduction Repair of post-TURP sphincter urethral strictures represents challenging problem, due to the risk of urinary incontinence after the repair. We described a surgical technique we use to repair these strictures preserving urinary continence in patients with incompetent bladder neck. Materials and methods An observational, retrospective, study was conducted to include patients with post-TURP urethral strictures in the area of distal sphincter. We included only patients with complete clinical data and follow-up who previously underwent TURP or HOLEP or TUIP, and subsequently developed proximal bulbar urethral strictures close to the membranous urethra and the related distal urethral sphincter. Patients were included, if they were fully continent after TURP or other procedures to treat BPH. The primary outcome of the study was treatment failure, defined as the need for any post-operative instrumentation. Secondary outcome was post-urethroplasty urinary continence. Patients showing stricture recurrence or post-operative incontinence were classified as failure. Results Overall, 69 patients were included in the study. Median patient's age was 67 years; median stricture length was 4 cm. Thirty-tree patients (47.8%) underwent previous urethrotomy. Median follow-up was 52 months. Out of 69 patients, 55 (79.7%) were classified as success and 14 (20.3%) as failure. Out of the whole cohort, thus, 11/69 (16%) have a risk of recurrent strictures and 3/69 (4.3%) have incontinence. Conclusions The use of modified ventral onlay graft urethroplasty, using particular non-aggressive steps, is a suitable surgical technique for repair of sphincter urethral stricture in patients who underwent BPH transurethral surgery, using different procedures (TURP, HOLEP, TUIP)
Risk calculator for prediction of treatment-related urethroplasty failure in patients with penile urethral strictures
Purpose To design a dedicated risk calculator for patients with penile urethra stricture who are scheduled to urethroplasty that might be used to counsel patients according to their pre-operative risk of failure. Methods Patients treated with penile urethroplasty at our center (1994-2018) were included in the study. Patients received 1-stage or staged penile urethroplasty. Patients with failed hypospadias repair, lichen sclerosus or incomplete clinical records were excluded. Treatment failure was defined as any required postoperative instrumentation, including dilation. Univariable Cox regression identified predictors of post-operative treatment failure and Kaplan-Meier analysis plotted the failure-free survival rates according to such predictors. Multivariable Cox regression-based risk calculator was generated to predict the risk of treatment failure at 10 years after surgery. Results 261 patients met the inclusion criteria. Median follow-up was 113 months. Out of 216 patients, 201 (77%) were classified as success and 60 (23%) failures. Former smoker (hazard ratio [HR] 2.12, p = 0.025), instrumentation-derived stricture (HR 2.55, p = 0.006), and use of grafts (HR 1.83, p = 0.037) were predictors of treatment failure. Model-derived probabilities showed that the 10-year risk of treatment failure varied from 5.8 to 41.1% according to patient's characteristics. Conclusions Long-term prognosis in patients who underwent penile urethroplasty is uncertain. To date, our risk-calculator represents the first tool that might help physicians to predict the risk of treatment failure at 10 years. According to our model, such risk is largely influenced by the etiology of the stricture, the use of graft, and patient's smoking habits
Focus on Internal Urethrotomy as Primary Treatment for Untreated Bulbar Urethral Strictures: Results from a Multivariable Analysis
Background: The use of internal urethrotomy for treatment of urethral stricture remains a controversial topic in urology.Objective: To investigate outcomes and predictors of failure for internal urethrotomy as primary treatment for untreated bulbar urethral strictures.Design, setting, and participants: We performed a retrospective analysis of patients who underwent internal urethrotomy. Patients with bulbar urethral stricture who did not receive any previous treatment were included. Patients with traumatic, penile or posterior urethral strictures, lichen sclerosus, failed hypospadias repair, or stricture length >4 cm were excluded.Outcome measurements and statistical analysis: The primary outcome was treatment failure. Kaplan-Meyer plots were used to depict treatment failure-free survival. Univariate and multivariable Cox regression analyses were used to test the association between predictors (age, body mass index, diabetes, history of smoking, etiology, stenosis type and length, preoperative maximum flow [pQ(max)]) and treatment failure.Results and limitations: Overall, 136 patients were included. The median stricture length was 2 cm. Median follow-up was 55 mo. At 5-yr follow-up the failure-free survival rate was 57%. On univariate analysis, diabetes, nonidiopathic etiology, stricture length of 3-4 cm, and pQ(max) were significantly associated with treatment failure. These predictors were included in a multivariable analysis, in which pQ(max) was the only significant predictor of treatment failure.Conclusions: Failure of internal urethrotomy for untreated bulbar urethral strictures greatly depends on pQ(max) flow at uroflowmetry. Patients with pQ(max >) 8 ml/s have a high probability of success, while patients with pQ(max) <5 ml/s have a low probability of success.Patient summary: The use of internal urethrotomy in patients with an untreated bulbar urethral stricture should only be considered in selected cases. (C) 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved
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