Metal-free design of a multilayered metamaterial with chirped Bragg grating for enhanced radiative cooling.

A wideband, all-dielectric metamaterial structure for enhancing radiative cooling is investigated. The structure is optimized to reflect most of the solar irradiance window (between 0.3 µm-3 µm), which is one of the biggest challenges in highly efficient radiative cooling coatings. The design is based on the principles of Bragg gratings, which constitutes a simple synthesis procedure to make a broadband reflector of reduced dimensions, without metallic layers, while keeping a flat enough response in the entire bandwidth. Numerical results show that reflection of solar irradiation can be easily tailored and maximized using this method, as well as the net cooling power of the device, about ∼79 W/m2 at daytime (about double at night-time) and a temperature reduction of 23 K (assuming no heat exchange) and 7 K assuming a heat exchange coefficient of 10 W/m2/K, for a device and ambient temperatures of 300 K and 303 K, respectively. This occurs even in detriment of absorption in the atmospheric window (8 µm-13 µm). Results also show the importance of efficiently reflecting solar irradiance for such technologies and its relevance in synthesis and design without using metallic components.

Sífilis en hombres que tienen sexo con hombres: una alarma para la detección de infección por VIH / Syphilis in Men Who Have Sex With Men: A Warning Sign for HIV Infection

OBJETIVOS: Describir las características clinicoepidemiológicas de la sífilis en la población de hombres que tienen sexo con hombres en un área de Mallorca. MÉTODOS: Revisión retrospectiva de los casos de sífilis en pacientes hombres que tienen sexo con hombres (HSH) entre enero de 2005 y junio de 2013 en un hospital de Mallorca. RESULTADOS: Encontramos 55 casos de sífilis en HSH, el 34,3% de los casos de sífilis del periodo de estudio. El 74,5% tenían coinfección por el virus de la inmunodeficiencia humana (VIH). El 70,7% de los diagnósticos de infección por VIH y sífilis fueron simultáneos. Los pacientes con infección por VIH tenían una mediana de CD4 de 456 (29-979). Se diagnosticaron por clínica el 49,1% y por cribado el 50,9% de los casos. La sífilis latente tardía o indeterminada fue la entidad más frecuente (41,9%). Los pacientes HSH tenían más riego de estar infectados por VIH que los varones no HSH. CONCLUSIONES: La mayoría de pacientes HSH con sífilis presentan coinfección por el VIH, siendo por lo tanto fundamental el cribado de VIH en estos pacientes, lo que incluso puede permitir un diagnóstico temprano de la misma

OBJECTIVE: To describe the clinical and epidemiological characteristics of syphilis in men who have sex with men (MSM) in an area of Mallorca, Spain. METHODS: We performed a retrospective analysis of syphilis cases in MSM seen at a hospital in Mallorca between January 2005 and June 2013. RESULTS: Fifty-five cases of syphilis were recorded in MSM during the study period (34.3% of all cases diagnosed), and 74.5% of these patients had human immunodeficiency virus (HIV) coinfection. The two diseases had been diagnosed simultaneously in 70.7% of this population. Patients with HIV coinfection had a median CD4 count of 456cells/μL (range, 29-979 cells/μL). Syphilis was diagnosed clinically in 49.1% of cases and by screening in the remaining 50.9%. The most common form of syphilis was late latent or indeterminate syphilis (41.9% of cases). In the group of men with syphilis, MSM had a higher risk of HIV infection. CONCLUSIONS: A majority of MSM with syphilis had HIV coinfection. HIV screening is therefore essential in this population and could even result in early diagnosis

Syphilis in Men Who Have Sex With Men: A Warning Sign for HIV Infection.

OBJECTIVE: To describe the clinical and epidemiological characteristics of syphilis in men who have sex with men (MSM) in an area of Mallorca, Spain. METHODS: We performed a retrospective analysis of syphilis cases in MSM seen at a hospital in Mallorca between January 2005 and June 2013. RESULTS: Fifty-five cases of syphilis were recorded in MSM during the study period (34.3% of all cases diagnosed), and 74.5% of these patients had human immunodeficiency virus (HIV) coinfection. The two diseases had been diagnosed simultaneously in 70.7% of this population. Patients with HIV coinfection had a median CD4 count of 456cells/µL (range, 29-979 cells/µL). Syphilis was diagnosed clinically in 49.1% of cases and by screening in the remaining 50.9%. The most common form of syphilis was late latent or indeterminate syphilis (41.9% of cases). In the group of men with syphilis, MSM had a higher risk of HIV infection. CONCLUSIONS: A majority of MSM with syphilis had HIV coinfection. HIV screening is therefore essential in this population and could even result in early diagnosis.