In this paper we construct spherical thin-shell wormholes supported by a Chaplygin gas. For a rather general class of geometries we introduce a new approach for the stability analysis of static solutions under perturbations preserving the symmetry. We apply this to wormholes constructed from Schwarzschild, Schwarzschild--de Sitter, Schwarzschild--anti-de Sitter, and Reissner-Nordstr\"om metrics. In the last two cases, we find that there are values of the parameters for which stable static solutions exist.
Good clinical results may be achieved with electrical stimulation in many fields of medicine. After a long period of experimental research, electrical stimulation has gained an important role in Urology too. Surgically implanted devices have been utilized only in recent years to cure neurogenic bladder, while external electrical stimulation with portable devices for female incontinence is well-defined in literature. Direct stimulation of detrusor muscle and sphincter was abandoned but, nowadays, selective neurostimulation seems to be very effective. In this paper, the most important surgical techniques are reviewed. Even if some of them are no longer used, knowledge of them is probably important to a better understanding of present results and future possibilities.
In this article we present a theoretical construction of spacetimes with a thin shell that joins two different local cosmic string geometries. We study two types of global manifolds, one representing spacetimes with a thin shell surrounding a cosmic string or an empty region with Minkowski metric, and the other corresponding to wormholes which are not symmetric across the throat located at the shell. We analyze the stability of the static configurations under perturbations preserving the cylindrical symmetry. For both types of geometries we find that the static configurations can be stable for suitable values of the parameters.
In the last years transrectal ultrasound has become a very important diagnostic tool of either benign or neoplastic prostatic disease. We can easily evaluate gland morphology and prostatic size by transrectal ultrasound. Intraoperatively, we can verify the complete removal of the adenoma in real time. Ultrasound definition of histopathological characteristics of benign prostatic hypertrophy gives us new prognostic and therapeutic information. In the near future, if alternative non-surgical therapies prove their effectiveness in some histological aspects ultrasound will enable us to choose the most correct treatment modality.
The aim of this study was to analyze the rates of positive surgical margins (PSM) after radical prostatectomy in patients undergoing robotic surgery (robot assisted laparoscopic prostatectomy [RALP]) compared with those undergoing open surgery (radical retropubic prostatectomy [RRP]), at an institution with medium case load.Retrospective consultation of a perspectively-maintained database that stores the data of all the patients submitted to radical prostatectomy at our institution since 1/2008. The indication to RRP vs. RALP was based almost exclusively on the period of the study: RRP was the sole available option between 1/2008 and 3/2010 and afterwards RALP become the standard of treatment, once a learning curve of 50 cases was concluded. A PSM was defined as the presence of cancer at the inked surface of prostate. A univariate and multivariate binary logistic regression estimated which factors were related to PSMs.The data of 576 patients (285 RRP, 291 RALP) were evaluated. The overall PSM rate was 28.1% (162/414 patients; 20.6% for pT2 stage, 51.8% for pT>2); overall PSM rate for RRP vs. RALP was 31.9% vs. 24.4 % (P=0.044). At multivariable analysis the factors related to the risk of PSM were stage pT>2 (RR 2.979, P=0.001), Gleason Score >6 (RR 1.662, P=0.026), the volume of tumor (RR 1.019, P=0.008) and the surgical technique (RALP vs. RRP, RR 0.647, P=0.039).In a series from a medium case-load institution, once data are adjusted for local staging, tumor volume and Gleason score, the risk of PSM is lower for RALP than RRP. This evidence could be of support for health-care practitioners to introduce robotic systems.
