61 research outputs found

    Pattern selection in the absolutely unstable regime as a nonlinear eigenvalue problem: Taylor vortices in axial flow

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    A unique pattern selection in the absolutely unstable regime of a driven, nonlinear, open-flow system is analyzed: The spatiotemporal structures of rotationally symmetric vortices that propagate downstream in the annulus of the rotating Taylor-Couette system due to an externally imposed axial through-flow are investigated for two different axial boundary conditions at the in- and outlet. Unlike the stationary patterns in systems without through-flow the spatiotemporal structures of propagating vortices are independent of parameter history, initial conditions, and system's length. They do, however, depend on the axial boundary conditions, the driving rate of the inner cylinder and the through-flow rate. Our analysis of the amplitude equation shows that the pattern selection can be described by a nonlinear eigenvalue problem with the frequency being the eigenvalue. Approaching the border between absolute and convective instability the eigenvalue problem becomes effectively linear and the selection mechanism approaches that one of linear front propagation. PACS:47.54.+r,47.20.Ky,47.32.-y,47.20.FtComment: 15 pages (LateX-file), 8 figures (Postscript

    European Association of Urology Guidelines Office Rapid Reaction Group: An Organisation-wide Collaborative Effort to Adapt the European Association of Urology Guidelines Recommendations to the Coronavirus Disease 2019 Era

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    The coronavirus disease 2019 (COVID-19) pandemic is unlike anything seen before by modern science-based medicine. As a scientific society, the European Association of Urology, via the guidelines, section offices, and the European Urology family of journals, we believe that it is important that we try to support urologists in this difficult situation. We aim to do this by providing tools that can facilitate decision making with the goal to minimise the impact and risks for both patients and health professionals delivering urological care, whenever possible, although it is clear that it is not always possible to mitigate them entirely. We hope that these revised recommendations will fill an important urological practice void and assist urologist surgeons across the globe as they do their very best to deal with the crisis of our generation

    Spotlight on Differentially Expressed Genes in Urinary Bladder Cancer

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    INTRODUCTION: We previously identified common differentially expressed (DE) genes in bladder cancer (BC). In the present study we analyzed in depth, the expression of several groups of these DE genes. MATERIALS AND METHODS: Samples from 30 human BCs and their adjacent normal tissues were analyzed by whole genome cDNA microarrays, qRT-PCR and Western blotting. Our attention was focused on cell-cycle control and DNA damage repair genes, genes related to apoptosis, signal transduction, angiogenesis, as well as cellular proliferation, invasion and metastasis. Four publicly available GEO Datasets were further analyzed, and the expression data of the genes of interest (GOIs) were compared to those of the present study. The relationship among the GOI was also investigated. GO and KEGG molecular pathway analysis was performed to identify possible enrichment of genes with specific biological themes. RESULTS: Unsupervised cluster analysis of DNA microarray data revealed a clear distinction in BC vs. control samples and low vs. high grade tumors. Genes with at least 2-fold differential expression in BC vs. controls, as well as in non-muscle invasive vs. muscle invasive tumors and in low vs. high grade tumors, were identified and ranked. Specific attention was paid to the changes in osteopontin (OPN, SPP1) expression, due to its multiple biological functions. Similarly, genes exhibiting equal or low expression in BC vs. the controls were scored. Significant pair-wise correlations in gene expression were scored. GO analysis revealed the multi-facet character of the GOIs, since they participate in a variety of mechanisms, including cell proliferation, cell death, metabolism, cell shape, and cytoskeletal re-organization. KEGG analysis revealed that the most significant pathway was that of Bladder Cancer (p = 1.5×10(-31)). CONCLUSIONS: The present work adds to the current knowledge on molecular signature identification of BC. Such works should progress in order to gain more insight into disease molecular mechanisms

    Reduced bleeding with DRY CUT ®

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    Genetic polymorphisms in the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene and prostate cancer risk in Caucasian men

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    Background: Catechol-estrogen metabolites can induce carcinogenesis by acting as endogenous tumor initiators. Glucuronidation, mediated by the UDP-glucuronosyltransferase 1A1 (UGT1A1) enzyme, is a main metabolic pathway of estrogen detoxification in steroid target tissues, such as the prostate. The aim of our study was to investigate the possible correlation between UGT1A1 promoter gene polymorphisms and prostate cancer risk. Patients and methods: 129 patients with prostate cancer and 260 healthy controls were included in our study. A(TA)TAA promoter polymorphism of UGT1A1 gene was studied using the Fragment Analysis Software of an automated DNA sequencer and three genotypes (homozygous 7/7, heterozygous 6/7 and normal homozygous 6/6) were identified. Results: No significant differences were observed between the cancer group and controls regarding the genotyping distribution of the three UGT1A1 promoter genotypes (P > 0.05). Also, no association was found between overall disease risk and the presence of the polymorphic homozygous genotype (TA(7)/TA(7) vs TA(6)/TA(7) + TA(6)/TA(6)) (P = 0.18). In addition, no association was revealed between UGT1A1 genotype distribution and Gleason score (P = 0.55). Conclusion: Our data suggest that the TA repeat polymorphism of UGT1A1 gene does not seem to alter prostate cancer risk susceptibility in Caucasian men. (c) 2010 Elsevier Ltd. All rights reserved

    Feasibility and efficacy of extracorporeal shock-wave lithotripsy using a new modified lateral position for the treatment of renal stones in obese patients

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    The aim of our study was to evaluate the efficacy and safety of ESWL using a modified lateral position in obese patients with renal stones. Nineteen obese patients with renal stones were enrolled (group A). The mean stone diameter was 1.3 cm (0.7-1.9 cm). The mean BMI was 35.1 kg/m2 (31-41 kg/m 2). Patients were placed in the lateral position, with the energy source facing their body posteriorly and the site where the stone was located in direct contact with the water cushion. Success rate (defined as the percentage of patients who were stone-free or with insignificant fragments after 3 months), mean number of ESWL sessions, mean duration of ESWL session and complications were recorded. The results were compared with those of 17 obese patients (Group B) with similar baseline characteristics treated in the standard supine position. All ESWLs were performed using the Dornier lithotripter SII. Both success rate (68.4 vs. 64.7% for groups A and B, respectively) and mean number of sessions (2.2 vs. 2.6) did not differ significantly between the two groups (p = 0.5). Interestingly, the time required to complete ESWL was significantly shorter for group A patients (56 min) compared to group B (73 min) (p = 0.001). No severe complications (including hematoma, pyelonephritis) were recorded. Our data indicate that ESWL in the modified lateral position for renal calculi in obese patients seems to be feasible and safe. In addition, it is faster than in the supine position since it overcomes technical difficulties. Further studies with a large number of patients are required to support our findings. © Springer-Verlag 2011

    Bladder stone formation after a tension-free vaginal tape procedure: Report on two cases

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    We present 2 cases of large bladder stones formed on a tension-free vaginal tape ( TVT) which was inadvertently passed through the bladder during the continence procedure. The stones together with the intravesical portion of the slings were removed using a suprapubic approach. High clinical suspicion of bladder complications is necessary when evaluating patients with urinary symptoms after a TVT operation. Copyright (C) 2007
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