Mejora de calidad de imagen de sistemas difusivos por absorción inducida

El fenómeno óptico de la difusión, también conocido como scattering o esparcimiento, siempre supone un obstáculo en los procesos, técnicas y aplicaciones ópticas; pues, aunque la exigencia en la precisión de los resultados no sea muy alta, si lo será con seguridad la pérdida de información que se produce. Es por ello que aquellas técnicas, sistemas o instrumentos que nos ayuden a mitigar los efectos producidos por este fenómeno ganan al menos cierta atención. En este proyecto exploramos uno de las posibles vías que nos podría ser útil en aquellas situaciones donde se requiera un cierto grado de precisión en la imagen y no se tenga por causa de algún sistema difusivo interpuesto. Esta vía consiste, como veremos, en la adición al sistema difusivo de un componente absorbente, que eliminaría en parte la radiación difundida causante de la turbidez de la imagen. Ya con anterioridad a este proyecto se demuestra la efectividad del carbón negro en polvo para conseguir dicha absorción. En el presente trabajo utilizaremos otros absorbentes, entre ellos el grafeno, estudiando las relativamente poco exploradas cualidades ópticas de este famoso material. ABSTRACT The scattering optical phenomena is always an obstacle in processes, techniques and optical applications, because, even in cases with a non required high level of accuracy of the results, the loss of information will surely be high. That is why those techniques, systems or instruments that help us to mitigate the effects produced by this phenomenon, deserve some attention. In this project we explore one of the possible methods that could be useful in situations in which a certain degree of precision in the image is required and we don't have it, due to some diffusive system interposed. This method, as we will see, consists on the addition to the diffusive system of an absorbent component, that would eliminate the scattered radiation that causes the turbidity of the image. Before this project, the effectiveness of carbon black powder to achieve this absorption was demonstrated. In the present work we will use other absorbers, including graphene, studying the relatively poorly explored optical characteristics of this famous material

Mycoses associated with AIDS in the Third World

Despite advances in diagnosis and treatment, the epidemiological status of the human immunodeficiency virus (HIV) infection is far from under control in most of the developing world. Sub-Saharan Africa, Southeast Asia and India show increased rates of new infections. In Latin America and the Caribbean there were 1.6 million estimated cases of HIV-infected patients at the end of 1997. Fungal diseases have been one of the most relevant diagnoses in relation to the acquired immunodeficiency syndrome (AIDS), Infections due to Candida species and Cryptococcus neoformans var, neoformans are common worldwide. Histoplasma capsulatum, Coccidioides immitis and Penicillium marneffei are important causes of disease in endemic areas. Infection due to Sporothrix schenckii, Blastomyces dermatitidis and Paracoccidioides brasiliensis are uncommon even where they are endemic. Phaeohyphomycetes, hyalohyphomycetes and zygomycetes are still rare as a cause of disease among AIDS patients, However, agents pertaining to these groups, such as Aspergillus spp., have an increasing incidence. Superficial mycoses due to dermatophytes have special features from epidemiological, clinical and therapeutic points of view

Dysphonia and laryngeal sequelae in paracoccidioidomycosis patients: a morphological and phoniatric study

The larynx is the third most commonly involved organ in paracoccidioidomycosis (PCM). While a few studies have evaluated laryngeal sequelae, there have not been any investigations of voice abnormalities in PCM patients. To evaluate persistent dysphonia and laryngeal lesions, we studied 15 normal subjects and 30 post-treatment PCM patients, i.e., 15 with only pulmonary and 15 with both laryngeal and pulmonary involvement. Perceptual and acoustic voice analysis were performed with all patients, while endoscopic studies were also conducted with the 15 laryngeal patients. Voice analysis showed instability by perceptual analysis (P < 0.01) in both groups, but more severe dysphonia was noted in the laryngeal group (P < 0.01). The dysponia, seen in 66.7% of these patients (dysphonia index < 7.0), was characterized by roughness and breathness. The Dr. Speech (Tiger Electronics) analysis program did not accept five voices from the laryngeal group due to the severe dysphonia. Jitter was elevated in five laryngeal lesion patients. Endoscopy showed that 80% of patients with laryngeal lesion had two or more laryngeal structures involved. Vocal fold alterations were seen in all laryngeal lesion patients, which included involvement of the arythenoids, epiglottis, and vestibular folds. This first functional study of laryngeal sequelae in PCM revealed frequent and severe dysphonia that may have important social consequences for patients

Use of algorithms for semi-automatic quantification of pulmonary fibrosis and emphysema

Obtaining a semi-automatic quantification of pathologies found in the lung, through images of high resolution computed tomography (HRCT), is of great importance to aid in medical diagnosis. Paraccocidioidomycosis (PCM) is a systemic disease that affects the lung and even after effective treatment leaves sequels such as pulmonary fibrosis and emphysema. It is very important to the area of tropical diseases that the lung injury be quantified more accurately. In this stud, we propose the development of algorithms in computational environment Matlab® able to objectively quantify lung diseases such as fibrosis and emphysema. The program consists in selecting the region of interest (ROI), and through the use of density masks and filters, obtaining the lesion area quantification in relation to the healthy area of the lung. The proposed method was tested on 15 exams of HRCT of patients with confirmed PCM. To prove the validity and effectiveness of the method, we used a virtual phantom, also developed in this research. © 2013 Springer-Verlag