16 research outputs found
Ultracold Bosons with 3-Body Attractive Interactions in an Optical Lattice
We study the effect of an optical lattice (OL) on the ground-state properties
of one-dimensional ultracold bosons with three-body attraction and two-body
repulsion, which are described by a cubic-quintic Gross-Pitaevskii equation
with a periodic potential. Without the OL and with a vanishing two-body
interaction term, soliton solutions of the Townes type are possible only at a
critical value of the three-body interaction strength, at which an infinite
degeneracy of the ground-state occurs; a repulsive two-body interaction makes
such localized solutions unstable. We show that the OL opens a stability window
around the critical point when the strength of the periodic potential is above
a critical threshold. We also consider the effect of an external parabolic
trap, studying how the stability of the solitons depends on matching between
minima of the periodic potential and the minimum of the parabolic trap.Comment: Special issue of European Physical Journal B on the conference
"Theory of Quantum Gases and Quantum Coherence" held in Grenoble, 200
One-Dimensional Bose Gases with N-Body Attractive Interactions
We study the ground state properties of a one-dimensional Bose gas with
N-body attractive contact interactions. By using the explicit form of the
bright soliton solution of a generalized nonlinear Schroedinger equation, we
compute the chemical potential and the ground state energy. For N=3, a
localized soliton wave-function exists only for a critical value of the
interaction strength: in this case the ground state has an infinite degeneracy
that can be parameterized by the chemical potential. The stabilization of the
bright soliton solution by an external harmonic trap is also discussed, and a
comparison with the effect of N-body attractive contact interactions in higher
dimensions is presented.Comment: 12 pages, 8 Postscript figure
Stereotactic ablative radiation therapy in renal cell carcinoma: From oligometastatic to localized disease.
Renal Cell Carcinoma (RCC) has historically been considered a radioresistant cancer, and radiotherapy was usually delivered with a palliative goal. Stereotactic ablative radiotherapy (SABR) allows the delivery of high doses on small treatment volumes in a safe and effective way, thus opening the doors to new applicationsof radiotherapy both in the treatment of the primary and oligometastasic disease. Aim of the current review is to explore the state of art of SABR in the therapeutic approach to RCC
Stereotactic ablative radiation therapy in renal cell carcinoma : from oligometastatic to localized disease
Renal Cell Carcinoma (RCC) has historically been considered a radioresistant cancer, and radiotherapy was usually delivered with a palliative goal. Stereotactic ablative radiotherapy (SABR) allows the delivery of high doses on small treatment volumes in a safe and effective way, thus opening the doors to new applicationsof radiotherapy both in the treatment of the primary and oligometastasic disease. Aim of the current review is to explore the state of art of SABR in the therapeutic approach to RCC
Radiotherapy in patients with HIV: current issues and review of the literature
Although the introduction of highly active antiretroviral therapy has radically improved the life expectancy of patients with HIV, HIV positivity is still considered a major barrier to oncological treatment for patients with cancer because of their worse prognosis and increased susceptibility to toxic effects compared with patients who are immunocompetent. The use of radiotherapy with or without chemotherapy, immunotherapy, or molecular targeted therapy is the standard of care for several cancers. These new drugs and substantial improvements in radiotherapy techniques, including intensity-modulated radiotherapy, image-guided radiotherapy, and stereotactic ablative radiotherapy, are optimising the feasibility of such anticancer treatments and are providing new opportunities for patients with cancer and HIV. In this Review, we discuss the role of radiotherapy, with or without chemotherapy or new drugs, in the treatment of cancer in patients with HIV, with a focus on the efficacy and tolerability of this approach on the basis of available evidence. Moreover, we analyse and discuss the biological basis of interactions between HIV and radiotherapy, evidence from preclinical studies, and immunomodulation by radiotherapy in the HIV setting