1,440 research outputs found
Non-homogeneous combinatorial manifolds
In this paper we extend the classical theory of combinatorial manifolds to
the non-homogeneous setting. NH-manifolds are polyhedra which are locally like
Euclidean spaces of varying dimensions. We show that many of the properties of
classical manifolds remain valid in this wider context. NH-manifolds appear
naturally when studying Pachner moves on (classical) manifolds. We introduce
the notion of NH-factorization and prove that PL-homeomorphic manifolds are
related by a finite sequence of NH-factorizations involving NH-manifolds.Comment: 18 pages, 6 figure
Dendritic Cells Are the Intriguing Players in the Puzzle of Idiopathic Pulmonary Fibrosis Pathogenesis
Idiopathic pulmonary fibrosis (IPF) is the most devastating progressive interstitial lung disease that remains refractory to treatment. Pathogenesis of IPF relies on the aberrant cross-talk between injured alveolar cells and myofibroblasts, which ultimately leads to an aberrant fibrous reaction. The contribution of the immune system to IPF remains not fully explored. Recent evidence suggests that both innate and adaptive immune responses may participate in the fibrotic process. Dendritic cells (DCs) are the most potent professional antigen-presenting cells that bridge innate and adaptive immunity. Also, they exert a crucial role in the immune surveillance of the lung, where they are strategically placed in the airway epithelium and interstitium. Immature DCs accumulate in the IPF lung close to areas of epithelial hyperplasia and fibrosis. Conversely, mature DCs are concentrated in well-organized lymphoid follicles along with T and B cells and bronchoalveolar lavage of IPF patients. We have recently shown that all sub-types of peripheral blood DCs (including conventional and plasmacytoid DCs) are severely depleted in therapy naĂŻve IPF patients. Also, the low frequency of conventional CD1c+ DCs is predictive of a worse prognosis. The purpose of this mini-review is to focus on the main evidence on DC involvement in IPF pathogenesis. Unanswered questions and opportunities for future research ranging from a better understanding of their contribution to diagnosis and prognosis to personalized DC-based therapies will be explored
A bird's eye view on the role of dendritic cells in SARS-CoV-2 infection: Perspectives for immune-based vaccines
Coronavirus disease-19 (COVID-19) is a complex disorder caused by the pandemic diffusion of a novel coronavirus named SARS-CoV-2. Clinical manifestations vary from silent infection to severe pneumonia, disseminated thrombosis, multi-organ failure, and death. COVID-19 pathogenesis is still not fully elucidated, while increasing evidence suggests that disease phenotypes are strongly related to the virus-induced immune system's dysregulation. Indeed, when the virus-host cross talk is out of control, the occurrence of an aberrant systemic inflammatory reaction, named “cytokine storm,” leads to a detrimental impairment of the adaptive immune response. Dendritic cells (DCs) are the most potent antigen-presenting cells able to support innate immune and promote adaptive responses. Besides, DCs play a key role in the anti-viral defense. The aim of this review is to focus on DC involvement in SARS-CoV-2 infection to better understand pathogenesis and clinical behavior of COVID-19 and explore potential implications for immune-based therapy strategies
Nonequilibrium electron energy distribution in Au under subpicosecond laser irradiation: A kinetic study
We have performed a kinetic study of the electron dynamic
relaxation inside a Au film subjected to a subpicosecond laser
pulse. For this purpose, we have developed a time-dependent
numerical solution of the Boltzmann equation for the electrons
inside the film considering the collision integrals due to
electron–electron and electron–phonon collisions
and a perturbation term due to the laser pulse. Our results
show that, after the pulse excitation, electron distributions
are very far from equilibrium. Therefore it is not possible,
especially in the first part of the temporal evolution, to describe
the relaxation of the electron distribution through a
two-temperature model
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