617 research outputs found
Intraocular Biopsy and ImmunoMolecular Pathology for "Unmasking" Intraocular Inflammatory Diseases
Intraocular inflammation can hide a variety of eye pathologies. In 33% of cases, to obtain a correct diagnosis, investigation of the intraocular sample is necessary. The combined analyses of the intraocular biopsy, using immuno-pathology and molecular biology, point to resolve the diagnostic dilemmas in those cases where history, clinical tests, and ophthalmic and systemic examinations are inconclusive. In such situations, the teamwork between the ophthalmologist and the molecular pathologist is critically important to discriminate between autoimmune diseases, infections, and intraocular tumors, including lymphoma and metastases, especially in those clinical settings known as masquerade syndromes. This comprehensive review focuses on the diagnostic use of intraocular biopsy and highlights its potential to enhance research in the field. It describes the different surgical techniques of obtaining the biopsy, risks, and complication rates. The review is organized according to the anatomical site of the sample: I. anterior chamber containing aqueous humor, II. iris and ciliary body, III. vitreous, and IV. choroid and retina. We have excluded the literature concerning biopsy for choroidal melanoma and retinoblastoma, as this is a specialized area more relevant to ocular oncology
The gravitational eikonal: from particle, string and brane collisions to black-hole encounters
Motivated by conceptual problems in quantum theories of gravity, the
gravitational eikonal approach, inspired by its electromagnetic predecessor,
has been successfully applied to the transplanckian energy collisions of
elementary particles and strings since the late eighties, and to string-brane
collisions in the past decade. After the direct detection of gravitational
waves from black-hole mergers, most of the attention has shifted towards
adapting these methods to the physics of black-hole encounters. For such
systems, the eikonal exponentiation provides an amplitude-based approach to
calculate classical gravitational observables, thus complementing more
traditional analytic methods such as the Post-Newtonian expansion, the
worldline formalism, or the Effective-One-Body approach. In this review we
summarize the main ideas and techniques behind the gravitational eikonal
formalism. We discuss how it can be applied in various different physical
setups involving particles, strings and branes and then we mainly concentrate
on the most recent developments, focusing on massive scalars minimally coupled
to gravity, for which we aim at being as self-contained and comprehensive as
possible.Comment: 208 pages, 19 figure
Sirtuins and redox signaling interplay in neurogenesis, neurodegenerative diseases, and neural cell reprogramming
Since the discovery of Neural Stem Cells (NSCs) there are still mechanism to be clarified, such as the role of mitochondrial metabolism in the regulation of endogenous adult neurogenesis and its implication in neurodegeneration. Although stem cells require glycolysis to maintain their stemness, they can perform oxidative phosphorylation and it is becoming more and more evident that mitochondria are central players, not only for ATP production but also for neuronal differentiation's steps regulation, through their ability to handle cellular redox state, intracellular signaling, epigenetic state of the cell, as well as the gut microbiota-brain axis, upon dietary influences. In this scenario, the 8-oxoguanine DNA glycosylase (OGG1) repair system would link mitochondrial DNA integrity to the modulation of neural differentiation. On the other side, there is an increasing interest in NSCs generation, from induced pluripotent stem cells, as a clinical model for neurodegenerative diseases (NDs), although this methodology still presents several drawbacks, mainly related to the reprogramming process. Indeed, high levels of reactive oxygen species (ROS), associated with telomere shortening, genomic instability, and defective mitochondrial dynamics, lead to pluripotency limitation and reprogramming efficiency's reduction. Moreover, while a physiological or moderate ROS increase serves as a signaling mechanism, to activate differentiation and suppress self-renewal, excessive oxidative stress is a common feature of NDs and aging. This ROS-dependent regulatory effect might be modulated by newly identified ROS suppressors, including the NAD(+)-dependent deacetylase enzymes family called Sirtuins (SIRTs). Recently, the importance of subcellular localization of NAD synthesis has been coupled to different roles for NAD in chromatin stability, DNA repair, circadian rhythms, and longevity. SIRTs have been described as involved in the control of both telomere's chromatin state and expression of nuclear gene involved in the regulation of mitochondrial gene expression, as well as in several NDs and aging. SIRTs are ubiquitously expressed in the mammalian brain, where they play important roles. In this review we summarize the current knowledge on how SIRTs-dependent modulation of mitochondrial metabolism could impact on neurogenesis and neurodegeneration, focusing mainly on ROS function and their role in SIRTs-mediated cell reprogramming and telomere protection
The eikonal operator at arbitrary velocities I: the soft-radiation limit
Observables related to the real part of the gravitational eikonal, such as
the deflection angle and time delay, have been found so far to have a smooth
post-Minkowskian (PM) expansion whose validity extends from the
non-relativistic to the most extreme ultra-relativistic (UR) regime, which
smoothly connects with massless particle collisions. To describe gravitational
radiation, the eikonal phase has to be promoted to a unitary operator for which
we motivate a proposal and start discussing properties in the soft-radiation
limit. A convergent PM expansion is found to only hold below an UR bound
(discussed in the GR literature in the seventies) above which a different
expansion is instead needed implying, in general, some non-analyticity in
Newton's constant. In this extreme UR regime soft radiative observables receive
contributions only from gravitons and are therefore universal. This generalises
the pattern discussed in \cite{DiVecchia:2020ymx} beyond the elastic case.Comment: 28 pages+reference
Alta resolución diagnóstica de la sonografía para determinar desinserción del menisco
Se evaluó la capacidad de la sonografía en tiempo real para reconocer
las lesiones de menisco. Se estudiaron por sonografía 124 rodillas en 62 pacientes con
sospecha de lesión de menisco, correlacionandose los hallazgos con el examen
clínico, la artrografía y la artroscopia.
El estudio se llevó a cabo en el Departamento de Radiología y Ortopedia del Hospital
Clementito Fraga Filho, entre los años 1995 y 2002. De los 50 diagnósticos
confirmados de lesión del menisco, 36 presentaron alteraciones sonográficas. La
desinserción del menisco se confirmó con cirugía en 24 pacientes, siendo bien
visualizadas y reconocidas las alteraciones por sonografía en 22 de ellos, en tanto que
se les identificó artrográficamente solo en 14 casos.
Se encontraron algunos signos sonográficos muy específicos en el menisco con
desinserción como área hipoecogénica en la base y fragmentación en 83.3% de los
casos dando certeza en el diagnóstico de lesión en un porcentaje alto. Se concluye que
la evaluación sonográfica es útil y debe ser considerada como método diagnóstico en
los casos de sospecha de lesión del menisco.Trabajo académic
Chapter Nemesi tecnologica, pace distopica: l’espropriazione della pace
Umberto Gori has often focused on the subject of peace, seen as the primary objective of Political Science, analysing the challenges that peacebuilding processes have to face in an international context undergoing profound change, and with aspects that could be described as dystopic. We will explore these dynamics by drawing inspiration from the way in which Ivan Illich dealt with the theme of the forced medicalisation of society, a theme that presents many points of contact with the intention of imposing a distorted version of the concept of peace, where a model of peaceful coexistence is proposed, which does not arise from the development of stable harmonious relations between mutually free and independent subjects, but from an absence of conflict produced by dehumanising forms of social conditioning
- …