0000000000537803
AUTHOR
E. Messina
showing 6 related works from this author
Asymptotic stability of solutions to Volterra-renewal integral equations with space maps
2012
Abstract In this paper we consider linear Volterra-renewal integral equations (VIEs) whose solutions depend on a space variable, via a map transformation. We investigate the asymptotic properties of the solutions, and study the asymptotic stability of a numerical method based on direct quadrature in time and interpolation in space. We show its properties through test examples.
An adaptive method for Volterra–Fredholm integral equations on the half line
2009
AbstractIn this paper we develop a direct quadrature method for solving Volterra–Fredholm integral equations on an unbounded spatial domain. These problems, when related to some important physical and biological phenomena, are characterized by kernels that present variable peaks along space. The method we propose is adaptive in the sense that the number of spatial nodes of the quadrature formula varies with the position of the peaks. The convergence of the method is studied and its performances are illustrated by means of a few significative examples. The parallel algorithm which implements the method and its performances are described.
Epidemiology of pancreatic neuroendocrine neoplasms. a gender perspective
2020
Purpose: Pancreatic neuroendocrine neoplasms (PNENs) are a group of clinically rare and heterogeneous tumors of the pancreas. Currently there are no studies investigating the gender difference in PNEN susceptibility. Thus, the purpose of this study was aimed at examining how gender shapes risk factors, clinicopathological features, and comorbidities in PNENs. Methods: The study design consisted of an Italian multicenter, retrospective study. The study included all consecutive patients with PNENs followed at the participating centers. Two hundred and twenty-nine patients (105 males,124 females, age 54 ± 0.98 years) with PNENs were enrolled at the participating centers. The clinicopathologica…
A rare rarity: neuroendocrine tumor of the esophagus
2019
Abstract Esophageal Neuroendocrine tumors (NETs) are rare, aggressive and lacking specific symptoms. This causes a diagnostic delay, worsening the prognosis. Numerous cases are reported in literature, without a consensus on the management. Our aim was to clarify epidemiology, clinical presentation, diagnostic, therapeutic management of esophageal NETs. Extensive literature search identified a total of 226 articles. One hundred twenty-five articles (n = 1676) met the inclusion criteria, showing that: the incidence of esophageal NET varies geographically; men (60–70 years) are more affected; smoking and alcohol abuse are the major risk factors; dysphagia, weight loss, appetite loss are the mo…