PubMed Health⌕ Search

Biomedical subjects

A Masiero

Publications and source records attributed to A Masiero.

15 recordsLinked to original sources
PubMed2004

Grand unification of quark and lepton flavor changing neutral currents.

In the context of supersymmetric grand unified theories with soft breaking terms arising at the Planck scale, it is generally possible to link flavor changing neutral current and CP violating processes occurring in the leptonic and hadronic sectors. We study the correlation between flavor changing squark and slepton mass insertions in models à la SU(5). We show that the constraints coming from lepton flavor violation exhibit a strong impact on CP-violating B decays.

Journal Article↗
PubMed2001

Nonlocal symmetry breaking in Kaluza-Klein theories.

Scherk-Schwarz gauge symmetry breaking of a D-dimensional field theory model compactified on a circle is analyzed. It is explicitly shown that forbidden couplings in the unbroken theory appear in the one-loop effective action only in a nonlocal way, implying that they are finite at all orders in perturbation theory. This result can be understood as a consequence of the local gauge symmetry, but it holds true also in the global limit.

Journal Article↗
PubMed2001

CP Violation and Flavor Changing Effects in K and B Mesons from Nonuniversal Soft Breaking Terms.

We analyze CP violation and flavor changing effects in a minimal supersymmetric standard model with arbitrary nonuniversal soft breaking. Large flavor changing neutral current effects are naturally expected in the K system, even in the absence of quark-squark flavor misalignment. However, the B system is sensitive to new supersymmetric contributions only if nonuniversality implies, not only different soft terms for the three generations but also a large quark-squark misalignment. The only exceptions are processes with a leading chirality changing contribution proportional to tanbeta (as b-->sgamma).

Journal Article↗
PubMed1998

A simple, low-cost and fast Peltier thermoregulation set-up for electrophysiology.

Most of the parameters recorded in electrophysiology are strongly temperature dependent. In order to control temperature fluctuations we have built a system that ensures an accurate thermoregulation of the recording chamber. Temperature of physiological preparations can be changed relatively quickly (about 8 degrees C/min) and with a good accuracy (+/- 0.5 degrees C) without inducing thermal oscillations. Contrary to other thermoregulating devices, the temperature regulation is not carried out through the perfused medium but directly at the bottom of the chamber where a 3-cm2 Peltier element has been placed. The element is driven by a dedicated electronic device which controls the amount and the direction of the current flowing across the Peltier thermocouple. All construction details and the appropriate electrical circuits are provided. Using this home-made device, the steady-state chamber temperature could be precisely monitored with a resolution of +/- 0.1 degrees C in a range of 0-40 degrees C. This set-up was tested in experiments designed to evaluate the temperature dependence of synaptic transmission in the Torpedo nerve electroplate synapses and of calcium currents recorded from isolated nerve cells. This low-cost method is suitable for a wide range of applications.

Animals↗
PubMed1992

[Major ambulatory surgery: organizational models].

In this essay, the authors provide a definition for those medical care facilities representing a consolidated alternative to traditional hospitalization. These facilities can be basically ascribed to the following patterns: day case surgery; day-hospital activity; home-care. Day case surgery is a complex and, in most cases, interdisciplinary procedure; this type of activity necessitates a pre-hospitalization period and often also a "protected discharge" or even a home-care service. Some specific criteria regarding day surgery activity have been defined as follows: the main criteria have a clinical nature, but they interact with others belonging to a social and structural-organizational order. The Royal College of Surgeons of United Kingdom has officially recognized in 1985 this medical care typology as one of the constituents of surgical care, and has evaluated that at least 1/3 of the overall operations could be carried out as day care surgery. In the United States, besides hospital and ambulatory surgery activity, a new pattern known as "free-standing center" has been promoted; in 1993, 35% of the operations is expected to be carried out in day case surgery centers. As far as Italy is concerned, in 1988 only day-hospital practice has been adequately recognized as an alternative medical care facility to traditional hospitalization. The Emilia Romagna region, in order to increase day case surgery activity, has issued in 1991 a list of 53 DRGs, in which day bed units treatment was possible. Up to now, however, only a small part of these diseases is treated on a day case surgery basis.

Ambulatory Care Facilities↗