6,437 research outputs found

    Track Momentum Discrimination Using Cluster Width in Silicon Strip Sensors for SLHC

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    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

    Haptics Rendering: Introductory Concepts

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    Repair of sphincter urethral strictures preserving urinary continence: surgical technique and outcomes

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    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

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    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

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    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

    Search for Point Sources of High Energy Neutrinos with AMANDA

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    This paper describes the search for astronomical sources of high-energy neutrinos using the AMANDA-B10 detector, an array of 302 photomultiplier tubes, used for the detection of Cherenkov light from upward traveling neutrino-induced muons, buried deep in ice at the South Pole. The absolute pointing accuracy and angular resolution were studied by using coincident events between the AMANDA detector and two independent telescopes on the surface, the GASP air Cherenkov telescope and the SPASE extensive air shower array. Using data collected from April to October of 1997 (130.1 days of livetime), a general survey of the northern hemisphere revealed no statistically significant excess of events from any direction. The sensitivity for a flux of muon neutrinos is based on the effective detection area for through-going muons. Averaged over the Northern sky, the effective detection area exceeds 10,000 m^2 for E_{mu} ~ 10 TeV. Neutrinos generated in the atmosphere by cosmic ray interactions were used to verify the predicted performance of the detector. For a source with a differential energy spectrum proportional to E_{nu}^{-2} and declination larger than +40 degrees, we obtain E^2(dN_{nu}/dE) <= 10^{-6}GeVcm^{-2}s^{-1} for an energy threshold of 10 GeV.Comment: 46 pages, 22 figures, 4 tables, submitted to Ap.

    Initial study of deep inelastic scattering with ZEUS at HERA

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    Results are presented on neutral current, deep inelastic scattering measured in collisions of 26.7 GeV electrons and 820 GeV protons. The events typically populate a range in Q2 from 10 to 100 GeV2. The values of x extend down to x ∌ 10-4 which is two orders of magnitude lower than previously measured at such Q2 values in fixed target experiments. The measured cross sections are in accord with the extrapolations of current parametrisations of parton distributions. © 1993

    Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA

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    Inclusive photoproduction of D*+- mesons has been measured for photon-proton centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of 37 pb^-1. Total and differential cross sections as functions of the D* transverse momentum and pseudorapidity are presented in restricted kinematical regions and the data are compared with next-to-leading order (NLO) perturbative QCD calculations using the "massive charm" and "massless charm" schemes. The measured cross sections are generally above the NLO calculations, in particular in the forward (proton) direction. The large data sample also allows the study of dijet production associated with charm. A significant resolved as well as a direct photon component contribute to the cross section. Leading order QCD Monte Carlo calculations indicate that the resolved contribution arises from a significant charm component in the photon. A massive charm NLO parton level calculation yields lower cross sections compared to the measured results in a kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure
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