El ojo: Un rompecabezas diagnóstico: Estudio observacional descriptivo y revisión / The Eye: A Diagnostic Puzzle: Descriptive observational study and review

Se comunica una serie de casos, multicéntricos de la cual participaron cinco instituciones. La muestra fue de 17 pacientes, de los cuales 11 pertenecían al Hospital Dr. J.M. Cullen. Todos consultaron por compromiso orbitario y/o periorbitario. El compromiso en hombres fue de 23.4% y un 76.6% en mujeres. La edad media en años fue de 45.4 (17-69 años). Dentro de los diagnósticos encontrados, cinco casos fueron Enfermedad Relacionada con IgG4 (ER-IgG4), dos casos de Enfermedad de Erdheim Chester (EEC), dos Xantogranuloma, dos xantelasmas, un caso de metástasis de cáncer de mama, un caso de orbitopatía tiroidea, un caso de Amiloidosis con mieloma múltiple, y tres sin diagnóstico. Se revisan los diagnósticos diferenciales encontrados.

A series of multicentric cases is reported, of which five institutions participated. The sample was of 17 patients, of which 11 belonged to our Hospital, the Dr. J.M. Cullen Hospital. All consulted for orbital and/or periorbital commitment. The commitment in men was 23.4% and 76.6% in women. The average age in years was 45.4 (17-69 years). Among the diagnoses found, five cases were IgG4-Related Disease, two cases of Erdheim Chester Disease, two Xantogranuloma, two xanthelasmas, a case of breast cancer metastases, a case of thyroid orbitopathy, a case of Amyloidosis with multiple myeloma, and three without diagnosis. Differential diagnoses found are reviewed.

Viejas enfermedades conocidas que afectan la órbita: Presentación de un caso clínico y revisión / Old known diseases affecting the orbit: Presentation of a clinical case and review

Presentamos el caso de un paciente de 56 años con antecedente de Mieloma Múltiple, que evoluciona con inflamación periorbitaria de ambos parpados, bilateral, de coloración amarillenta-violácea, ulcerada e indolora. Se planteó el diagnóstico diferencial con las enfermedades xantogranulomatosas orbitarias del adulto, en especial con su asociación con Mieloma Múltiple (MM). Al realizar biopsia de la lesión, se observan en la histología fragmentación de haces de colágeno dérmico y alrededor de vasos un material amorfo acelular eosinófilo pálido, rojo congo positivo y coloración verde manzana con luz polarizada, llegando al diagnóstico de Amiloidosis y Xantogranuloma Orbitario del Adulto.

We present the case of a 56-year-old patient with a history of Multiple Myeloma, who evolves with periorbital inflammation of both eyelids, bilateral, yellowish-violet, ulcerated and painless. The differential diagnosis with the adult orbital xanthogranulomatous diseases was raised, especially XN due to its association with MM. When performing a biopsy of the lesion, fragmentation of dermal collagen bundles and around vessels a pale eosinophilic acellular material, positive congo red and apple-green color with polarized light are observed in the histology, reaching the diagnosis of Amyloidosis and Orbital Xantogranuloma of the Adult.

Self-similar transport, spin polarization and thermoelectricity in complex silicene structures.

2D materials open the possibility to study Dirac electrons in complex self-similar geometries. The two-dimensional nature of materials like graphene, silicene, phosphorene and transition-metal dichalcogenides allow the nanostructuration of complex geometries through metallic electrodes, interacting substrates, strain, etc. So far, the only 2D material that presents physical properties that directly reflect the characteristics of the complex geometries is monolayer graphene. In the present work, we show that silicene nanostructured in complex fashion also displays self-similar characteristics in physical properties. In particular, we find self-similar patterns in the conductance, spin polarization and thermoelectricity of Cantor-like silicene structures. These complex structures are generated by modulating electrostatically the silicene local bandgap in Cantor-like fashion along the structure. The charge carriers are described quantum relativistically by means of a Dirac-like Hamiltonian. The transfer matrix method, the Landauer-Büttiker formalism and the Cutler-Mott formula are used to obtain the transmission, transport and thermoelectric properties. We numerically derive scaling rules that connect appropriately the self-similar conductance, spin polarization and Seebeck coefficient patterns. The scaling rules are related to the structural parameters that define the Cantor-like structure such as the generation and length of the system as well as the height of the potential barriers. As far as we know this is the first time that a 2D material beyond monolayer graphene shows self-similar quantum transport as well as that transport related properties like spin polarization and thermoelectricity manifest self-similarity.

A physical model for dementia.

Aging associated brain decline often result in some kind of dementia. Even when this is a complex brain disorder a physical model can be used in order to describe its general behavior. A probabilistic model for the development of dementia is obtained and fitted to some experimental data obtained from the Alzheimer's Disease Neuroimaging Initiative. It is explained how dementia appears as a consequence of aging and why it is irreversible.

Self-similar conductance patterns in graphene Cantor-like structures.

Graphene has proven to be an ideal system for exotic transport phenomena. In this work, we report another exotic characteristic of the electron transport in graphene. Namely, we show that the linear-regime conductance can present self-similar patterns with well-defined scaling rules, once the graphene sheet is subjected to Cantor-like nanostructuring. As far as we know the mentioned system is one of the few in which a self-similar structure produces self-similar patterns on a physical property. These patterns are analysed quantitatively, by obtaining the scaling rules that underlie them. It is worth noting that the transport properties are an average of the dispersion channels, which makes the existence of scale factors quite surprising. In addition, that self-similarity be manifested in the conductance opens an excellent opportunity to test this fundamental property experimentally.

Perception of wholes and of their component parts: some configural superiority effects.

Theories of visual pattern recognition frequently assume that processing begins with an analysis of the pattern into component parts, which are often assumed to be line segments of particular orientations, lengths, positions, and curvatures. The present experiments measured discriminability of these simple parts when presented either in isolation or within configural contexts that provided no formal information useful for the discrimination. Certain contexts either impaired or did not affect performance. Other contexts were found, however, which dramatically improved discriminability. Thus, two patterns which differed only in a single part could be discriminated from each other more quickly than could their distinguishing parts shown in isolation. Further experiments suggest that this "configural superiority" effect influences perceptual components of processing rather than memorial components. The mechanism underlying configural superiority appears to be the detection of novel and distinguishing features, such as corners and intersections, which emerge when parts are placed in close proximity to each other. The outlines of a model for preattentive feature discrimination are presented.