Fundamentos Físicos de la Óptica de Multicapas

Cuando una onda plana llega a la superficie de separación de dos medios homogéneos con diferentes índices de refracción da lugar a una onda transmitida en el segundo medio y una onda reflejada en el primer medio. Se estudiarán las relaciones entre las amplitudes (coeficientes de reflexión y transmisión) e intensidades (reflectancia y transmitancia) de las ondas obteniendo las expresiones conocidas como fórmulas de Fresnel. Se abordará el estudio de las películas delgadas monocapa y multicapa que se utilizan en diversas aplicaciones físicas. Se introducirá un método matricial que aborda de modo más sencillo y sistemático el estudio de las películas multicapa.AMPARO PONS MARTI; Monsoriu Serra, JA.; Ferrando, V. (2021). Fundamentos Físicos de la Óptica de Multicapas. Escuela Técnica Superior de Ingeniería del Diseño. http://hdl.handle.net/10251/165249

Visual acuity with computer simulated and lens-induced astigmatism

[EN] The relationship between spherical and astigmatic refractive errors and their associated visual acuity is investigated in this work by means of two different approaches. In the first one, different refractive errors were induced in normal subjects by trial lenses. In the second one, defocused images were simulated numerically by the optical transfer function of a model eye and then judged by the same subjects. The amount of defocus (measured in terms of the modulus of the dioptric power vector) necessary to reduce the visual acuity to 0.1 logMAR and to 0.4 logMAR was computed with each method and then compared. We found that the visual system is clearly more tolerant to lens-induced defocus than for the computer simulated one. However, no significant differences in visual acuity were found for astigmatism of the same power but different axes in each method.We acknowledge financial support from Ministerio de Economia y Competitividad (Grant FIS2011-23175) and Generalitat Valenciana (PROMETEO II 2014-072), Spain. The authors would like to thank the anonymous reviewers for their valuable comments and suggestions to improve the quality of the paper.Remón Martín, L.; Benlloch, J.; Pons Marti, A.; Monsoriu Serra, JA.; Furlan, WD. (2014). Visual acuity with computer simulated and lens-induced astigmatism. OPTICA APPLICATA. 44(4):521-531. https://doi.org/10.5277/oa140403S52153144

Characteristics and laboratory findings on admission to the emergency department among 2873 hospitalized patients with COVID-19: the impact of adjusted laboratory tests in multicenter studies. A multicenter study in Spain (BIOCOVID-Spain study).

Identification of predictors for severe disease progression is key for risk stratification in COVID-19 patients. We aimed to describe the main characteristics and identify the early predictors for severe outcomes among hospitalized patients with COVID-19 in Spain. This was an observational, retrospective cohort study (BIOCOVID-Spain study) including COVID-19 patients admitted to 32 Spanish hospitals. Demographics, comorbidities and laboratory tests were collected. Outcome was in-hospital mortality. For analysis, laboratory tests values were previously adjusted to assure the comparability of results among participants. Cox regression was performed to identify predictors. Study population included 2873 hospitalized COVID-19 patients. Nine variables were independent predictors for in-hospital mortality, including creatinine (Hazard ratio [HR]:1.327; 95% Confidence Interval [CI]: 1.040-1.695, p = .023), troponin (HR: 2.150; 95% CI: 1.155-4.001; p = .016), platelet count (HR: 0.994; 95% CI: 0.989-0.998; p = .004) and C-reactive protein (HR: 1.037; 95% CI: 1.006-1.068; p = .019). This is the first multicenter study in which an effort was carried out to adjust the results of laboratory tests measured with different methodologies to guarantee their comparability. We reported a comprehensive information about characteristics in a large cohort of hospitalized COVID-19 patients, focusing on the analytical features. Our findings may help to identify patients early at a higher risk for an adverse outcome