RGB Achromatic Metalens Doublet for Digital Imaging.

Chromatic aberration is a major challenge faced by metalenses. Current methods to achieve broadband achromatic operation in metalenses usually suffer from limited size, numerical aperture, and working bandwidth due to the finite group delay of meta-atoms, thus restricting the range of practical applications. Multiwavelength achromatic metalenses can overcome those limitations, making it possible to realize larger numerical aperture (NA) and sizes simultaneously. However, they usually require three layers, which increases their fabrication complexity, and have only been demonstrated in small sizes, with low numerical aperture and modest efficiencies. Here, we demonstrate a 1 mm diameter red-green-blue achromatic metalens doublet with a designed NA of 0.8 and successfully apply the metalens in a digital imaging system. This work shows the potential of the doublet metasurfaces, extending their applications to digital imaging systems such as digital projectors, virtual reality glasses, high resolution microscopies, etc.

Broadband c-Si metasurfaces with polarization control at visible wavelengths: applications to 3D stereoscopic holography.

Visual arts and entertainment related industries are continuously looking at promising innovative technologies to improve users' experience with state-of-the-art visualization platforms. This requires further developments on pixel resolution and device miniaturization which can be achieved, for instance, with high contrast materials, such as crystalline silicon (c-Si). Here, a new broadband stereoscopic hologram metasurface is introduced, where independent phase control is achieved for two orthogonal polarizations in the visible spectrum. The holograms are fabricated with a birefringent metasurface consisting of elliptical c-Si nanoposts on Sapphire substrate. Two holograms are combined on the same metasurface (one for each polarization) where each is encoded with four phase levels. The theoretical bandwidth is 110 nm with a signal to noise ratio (SNR) >15 dB. The stereoscopic view is obtained with a pair of cross-polarized filters in front of the observers' eyes. The measured transmission and diffraction efficiencies are about 70% and 15%, respectively, at 532 nm (the design wavelength). The metasurfaces are also investigated at 444.9 nm and 635 nm to experimentally assess their bandwidth performance. The stereoscopic effect is surprisingly good at 444.9 nm (and less so at 635 nm) with transmission and diffraction efficiencies around 70% and 18%, respectively.

Highly efficient holograms based on c-Si metasurfaces in the visible range.

This paper reports on the first hologram in transmission mode based on a c-Si metasurface in the visible range. The hologram shows high fidelity and high efficiency, with measured transmission and diffraction efficiencies of ~65% and ~40%, respectively. Although originally designed to achieve full phase control in the range [0-2π] at 532 nm, these holograms have also performed well at 444.9 nm and 635 nm. The high tolerance to both fabrication and wavelength variations demonstrate that holograms based on c-Si metasurfaces are quite attractive for diffractive optics applications, and particularly for full-color holograms.

Progressive disseminated histoplasmosis in HIV-positive patients.

BACKGROUND: Histoplasmosis is the most common endemic mycosis among people living with advanced HIV infection. PURPOSE: Describe general aspects and challenges of this disease and its association with HIV. RESEARCH DESIGN: Review of literature. STUDY SAMPLE: Articles found using different combinations of terms including "disseminated histoplasmosis" and AIDS/HIV or immunosuppression in PubMed, Scopus, WHO Global health library, and Scielo database. ANALYSIS: We look for information on epidemiology, pathogenesis, diagnosis, and treatment of histoplasmosis in AIDS patients. RESULTS: Histoplasmosis is caused by Histoplasma capsulatum, a dimorphic fungus encountered throughout the world, mainly in soil enriched with bat and bird excreta. Progressive disseminated histoplasmosis is the main presentation of this mycosis in people living with advanced HIV and is fatal if left untreated. Symptoms include a systemic disease characterized by fever, weight loss, night sweats, skin manifestations, hepatomegaly, splenomegaly, and septic shock. Diagnostic tests include culture, visualization of H. capsulatum by direct and histopathological examination, serology, antigen, molecular, and skin testing. Patients with disseminated disease require aggressive and prolonged treatment to eradicate the pathogen and include amphotericin B and itraconazole. In many low income countries of endemic regions, histoplasmosis in HIV-positive patients is often undiagnosed or misdiagnosed as another opportunistic infection, due to the similarity in clinical manifestations and to the paucity of better diagnostic tests. CONCLUSION: Histoplasmosis remains a neglected disease. Few studies about the disease and expensive treatments make it difficult to reduce the morbidity and mortality of this condition. Public health services and physicians must be aware of histoplasmosis' burden among the HIV-positive population.

Clinical aspects of congenital microcephaly syndrome by Zika virus in a rehabilitation center for patients with microcephaly.

OBJECTIVE: In this study, we intend to identify the prevalence of clinical variables in children with microcephaly. METHODS: This is a cross-sectional and observational study with data collected from medical records of patients admitted to the microcephaly outpatient clinic of a referral center in Teresina-PI. Demographic (gender and age) and clinical data (presence of epilepsy, dysphagia, irritability, and associated comorbidities) were collected. The frequency of Zika virus as a probable etiology was determined from computed tomography patterns and the exclusion of other etiologies by serological tests. RESULTS: A total of 67 patient records were evaluated, of which 31 were male and 36 were female, with a mean age of 1 year and 10 months. The most prevalent clinical variables were epilepsy, present in 47 children (70.2%), and irritability in 37 (55.2%). Also with a high frequency, 22 had dysphagia (32.8%), and 13 had musculoskeletal comorbidities (19.4%). Only three patients in the sample had cardiac abnormalities (4.5%), and no endocrine comorbidity was found. A total of 38 children in the sample (56.7%) presented ZIKV as a probable etiology and, in these cases, there was a higher frequency of epilepsy and dysphagia compared to other etiologies, although not statistically significant. CONCLUSION: Epilepsy, irritability, dysphagia, and musculoskeletal comorbidities were the most frequent clinical variables in children with microcephaly. There was a high prevalence of congenital ZIKV microcephaly syndrome in this sample.

Atypical presentation and management of fibrodysplasia ossificans progressiva.

We report a case of an 18-year-old woman, with bilateral acute inflammatory pain on the hip area, during the premenstrual period, and progressive increase in volume and rigidity of both hips. Bilateral exuberant soft tissue calcifications were present on the radiographic exams, and the patient also presented with bilateral short-length hallux valgus. A heterozygous mutation in the protein kinase domain of ACVR1 gene was found, allowing the diagnosis of fibrodysplasia ossificans progressive. Due to the relation between the disease flares and the premenstrual period, the patient was put into a chemically induced amenorrhea, with no new inflammatory crises since.This case illustrates the importance of an accurate diagnosis to prevent unnecessary diagnostic procedures, as well as the need to develop specific treatment strategies to address each patient's particular needs.

Clinical aspects of congenital microcephaly syndrome by Zika virus in a rehabilitation center for patients with microcephaly

SUMMARY OBJECTIVE In this study, we intend to identify the prevalence of clinical variables in children with microcephaly. METHODS This is a cross-sectional and observational study with data collected from medical records of patients admitted to the microcephaly outpatient clinic of a referral center in Teresina-PI. Demographic (gender and age) and clinical data (presence of epilepsy, dysphagia, irritability, and associated comorbidities) were collected. The frequency of Zika virus as a probable etiology was determined from computed tomography patterns and the exclusion of other etiologies by serological tests. RESULTS A total of 67 patient records were evaluated, of which 31 were male and 36 were female, with a mean age of 1 year and 10 months. The most prevalent clinical variables were epilepsy, present in 47 children (70.2%), and irritability in 37 (55.2%). Also with a high frequency, 22 had dysphagia (32.8%), and 13 had musculoskeletal comorbidities (19.4%). Only three patients in the sample had cardiac abnormalities (4.5%), and no endocrine comorbidity was found. A total of 38 children in the sample (56.7%) presented ZIKV as a probable etiology and, in these cases, there was a higher frequency of epilepsy and dysphagia compared to other etiologies, although not statistically significant. CONCLUSION Epilepsy, irritability, dysphagia, and musculoskeletal comorbidities were the most frequent clinical variables in children with microcephaly. There was a high prevalence of congenital ZIKV microcephaly syndrome in this sample.

RESUMO OBJETIVO Pretende-se, neste estudo, identificar a prevalência de variáveis clínicas em crianças com microcefalia. MÉTODOS Trata-se de um estudo transversal e observacional com dados coletados de prontuários de pacientes admitidos no ambulatório de microcefalia de um centro de referência em Teresina (PI). Foram coletados dados demográficos (gênero Ve idade) e clínicos (presença de epilepsia, disfagia, irritabilidade e comorbidades associadas). A frequência de Zika vírus como provável etiologia foi determinada a partir de padrões da tomografia computadorizada e da exclusão de outras etiologias por exames sorológicos. RESULTADOS Foram avaliados 67 prontuários de pacientes, sendo 31 do sexo masculino e 36 do sexo feminino, com idade média de 1 ano e 10 meses. As variáveis clínicas mais prevalentes foram epilepsia, presente em 47 das crianças (70,2%), e irritabilidade, em 37 (55,2%). Também com elevada frequência, 22 possuíam quadro de disfagia (32,8%) e 13 apresentavam comorbidades osteomusculares (19,4%). Apenas três pacientes da amostra tinham quadro de alterações cardiológicas (4,5%) e nenhuma comorbidade endocrinológica foi encontrada. Trinta e oito crianças da amostra (56,7%) apresentaram ZIKV como provável etiologia e, nesses casos, houve maior frequência de epilepsia e disfagia em comparação com outras etiologias, embora não de forma significativa estatisticamente. CONCLUSÕES Epilepsia, irritabilidade, disfagia e comorbidades osteomusculares foram as variáveis clínicas mais frequentes em crianças com microcefalia. Houve uma prevalência alta de síndrome de microcefalia congênita por ZIKV nessa amostra.