Nucleon form factors and moments of parton distributions in twisted mass lattice QCD

We present results on the electroweak form factors and on the lower moments of parton distributions of the nucleon, within lattice QCD using two dynamical flavors of degenerate twisted mass fermions. Results are obtained on lattices with three different values of the lattice spacings, namely a=0.089 fm, a=0.070 fm and a=0.056 fm, allowing the investigation of cut-off effects. The volume dependence is examined by comparing results on two lattices of spatial length L=2.1 fm and L=2.8 fm. The simulations span pion masses in the range of 260-470 MeV. Our results are renormalized non-perturbatively and the values are given in the MS-scheme at a scale mu=2 GeV.Comment: Talk presented in the XXIst International Europhysics Conference on High Energy Physics, 21-27 July 2011, Grenoble, Rhones Alpes Franc

Nucleon scalar and tensor charges using lattice QCD simulations at the physical value of the pion mass

We present results on the light, strange and charm nucleon scalar and tensor charges from lattice QCD, using simulations with $N_f=2$ flavors of twisted mass Clover-improved fermions with a physical value of the pion mass. Both connected and disconnected contributions are included, enabling us to extract the isoscalar, strange and charm charges for the first time directly at the physical point. Furthermore, the renormalization is computed non-perturbatively for both isovector and isoscalar quantities. We investigate excited state effects by analyzing several sink-source time separations and by employing a set of methods to probe ground state dominance. Our final results for the scalar charges are $g_S^u = 5.20(42)(15)(12)$, $g_S^d = 4.27(26)(15)(12)$, $g_S^s=0.33(7)(1)(4)$, $g_S^c=0.062(13)(3)(5)$ and for the tensor charges $g_T^u = 0.782(16)(2)(13)$, $g_T^d = -0.219(10)(2)(13)$, $g_T^s=-0.00319(69)(2)(22)$, $g_T^c=-0.00263(269)(2)(37)$ in the $\overline{\rm MS}$ scheme at 2~GeV. The first error is statistical, the second is the systematic error due to the renormalization and the third the systematic arising from possible contamination due to the excited states.Comment: 20 pages and 13 figure

Does ureteral access sheath have an impact on ureteral injury?

Objective: To present a well-organized review about ureteral access sheath impact on ureteral injury. Materials and Methods: Systemic search on literature was done. Total of 3766 studies observed by two urologists and results were unified. A Prisma diagram was used for eliminating irrelevant studies and at the end of elimination process 28 studies were found eligible for this review. Results: Not only clinical studies but also comparative experimental animal studies show that there is no significant data to claim that ureteral access sheath insertion causes more ureteral injury. Pre-stented patients were found to be at lower risk for ureteral injury. Risk of progression to ureteral injury seems to be low even if ureteral injury occurs with insertion of ureteral access sheath. Conclusion: Summary of studies' results indicate that use of ureteral access sheath doesn't increase ureteral injury. This review may help understanding safety profile of ureteral access sheath on evidence-based level. There is not enough data to make a statement that ureteral access sheath prevents ureteral injury

First Physics Results at the Physical Pion Mass from Nf=2N_f = 2 Wilson Twisted Mass Fermions at Maximal Twist

We present physics results from simulations of QCD using $N_f = 2$ dynamical Wilson twisted mass fermions at the physical value of the pion mass. These simulations were enabled by the addition of the clover term to the twisted mass quark action. We show evidence that compared to previous simulations without this term, the pion mass splitting due to isospin breaking is almost completely eliminated. Using this new action, we compute the masses and decay constants of pseudoscalar mesons involving the dynamical up and down as well as valence strange and charm quarks at one value of the lattice spacing, $a \approx 0.09$ fm. Further, we determine renormalized quark masses as well as their scale-independent ratios, in excellent agreement with other lattice determinations in the continuum limit. In the baryon sector, we show that the nucleon mass is compatible with its physical value and that the masses of the $\Delta$ baryons do not show any sign of isospin breaking. Finally, we compute the electron, muon and tau lepton anomalous magnetic moments and show the results to be consistent with extrapolations of older ETMC data to the continuum and physical pion mass limits. We mostly find remarkably good agreement with phenomenology, even though we cannot take the continuum and thermodynamic limits.Comment: 45 pages, 15 figure

Progress in simulations with twisted mass fermions at the physical point

In this contribution, results from N_f=2Nf=2 lattice QCD simulations at one lattice spacing using twisted mass fermions with a clover term at the physical pion mass are presented. The mass splitting between charged and neutral pions (including the disconnected contribution) is shown to be around 20(20)~mathrm{MeV}20(20) MeV. Further, a first measurement using the clover twisted mass action of the average momentum fraction of the pion is given. Finally, an analysis of pseudoscalar meson masses and decay constants is presented involving linear interpolations in strange and charm quark masses. Matching to meson mass ratios allows the calculation of quark mass ratios: mu_s/mu_l=27.63(13)μs/μl=27.63(13), mu_c/mu_l=339.6(2.2)μc/μl=339.6(2.2) and mu_c/mu_s=12.29(10)μc/μs=12.29(10). From this mass matching the quantities f_K=153.9(7.5)~mathrm{MeV}fK=153.9(7.5) MeV, f_D=219(11)~mathrm{MeV}fD=219(11) MeV, f_{D_s}=255(12)~mathrm{MeV}fDs=255(12) MeV and M_{D_s}=1894(93)~mathrm{MeV}MDs=1894(93) MeV are determined without the application of finite volume or discretization artefact corrections and with errors dominated by a preliminary estimate of the lattice spacing

Combination Therapy with Alpha-blocker and Phosphodiesterase-5 Inhibitor for Improving Lower Urinary Tract Symptoms and Erectile Dysfunction in Comparison with Monotherapy: A Systematic Review and Meta-analysis

Treatment with the combination therapy is more effective for the improvement of the International Prostate System Score. Less significant improvement was shown in the maximum flow rate and postvoid residual. The beneficial effect of combination therapy regarding erectile dysfunction remains equivocal. The combination therapy seemed to be safe and well tolerated

The efficacy and safety of string stents after retrograde intrarenal surgery for urolithiasis

INTRODUCTION: Ureteral stent insertion is frequently chosen after upper tract endourological procedures. The use of stents carrying a suture string is sometimes used to facilitate the extraction of the stent. In this systematic review and meta-analysis, we aimed to provide stronger evidence for the efficacy of string stents, by comparing them to non-string stents, in matters of patients’ quality of life (QoL), stent-related symptoms (SRS) and complications. EVIDENCE ACQUISITION: A systematic review was conducted on PubMed, SCOPUS, Cochrane, EMBASE and Web of Science. The studies included were only comparative randomized controlled trials which included at least one group with tethered ureteral stent and one group with standard stent after the performance of endoscopic surgery for lithiasis of upper urinary tract. Primary endpoints were QoL expressed as general health, urinary symptoms as well as impact on work performance and SRS, expressed by VAS score. Secondary endpoints included complications such as stent migration, stent dislodgement, urinary tract infections (UTIs), emergency room visits and retained stent. EVIDENCE SYNTHESIS: We identified nine studies to be included in the qualitative synthesis and 3 randomized controlled trials to be included in the quantitative synthesis and the meta-analysis. The statistical difference in the stent related QoL was insignificant. General health was less affected in the non-string group. The urinary symptoms and the impact on work performance were similar between the groups. VAS pain score during the time that the patients were stented was insignificantly less in the non-string group, while VAS pain score was higher in the non-string group at extraction. Stent dislodgement was more frequent in the string group. There was no difference between the groups concerning the rate of UTIs. CONCLUSIONS: Non-string stents affected less the patients’ QoL, in terms of general health and urinary symptoms, caused less stent related pain in cases of stent in situ and caused stent dislodgment in fewer patients. On the contrary, string stents caused less pain at extraction. All the aforementioned differences did not reach statistical difference. (Cite this article as: Dellis A, Kallidonis P, Adamou C, Kostakopoulos N, Kotsiris D, Ntasiotis P, et al.; Urolithiasis and Endourology Working Party of the European Association of Urology (EAU) Young Academic Urologists (YAU).The efficacy and safety of string stents after retrograde intrarenal surgery for urolithiasis. © 2019 EDIZIONI MINERVA MEDIC