Broadband Radar Cross-Section Reduction Using AMC Technology Iriarte Galarregui, Juan Carlos; Tellechea Pereda, Amagoia; Martinez de Falcon, Jose Luis ...
IEEE transactions on antennas and propagation,
12/2013, Letnik:
61, Številka:
12
Journal Article
Recenzirano
Odprti dostop
This paper presents the design, fabrication, and characterization of a planar broadband chessboard structure to reduce the radar cross-section (RCS) of an object. The chessboard -like configuration ...is formed by combining two artificial magnetic conductor (AMC) cells. The bandwidth limitations intrinsic to AMC structures are overcome in this work by properly selecting the phase slope versus frequency of both AMC structures. A 180 ° phase difference has been obtained over more than 40% frequency bandwidth with a RCS reduction larger than 10 dB. The influence of the incidence angle in the working bandwidth has been performed. A good agreement between simulations and measurements is achieved.
Mounting evidence links poor sleep quality with a higher risk of late-life dementia. However, the structural and cognitive correlates of insomnia are still not well understood. The study aims were to ...characterize the cognitive performance and brain structural pattern of cognitively unimpaired adults at increased risk for Alzheimer's disease (AD) with insomnia.
This cross-sectional study included 1683 cognitively unimpaired middle/late-middle-aged adults from the ALFA (ALzheimer and FAmilies) study who underwent neuropsychological assessment, T1-weighted structural imaging (n = 366), and diffusion-weighted imaging (n = 334). The World Health Organization's World Mental Health Survey Initiative version of the Composite International Diagnostic Interview was used to define the presence or absence of insomnia. Multivariable regression models were used to evaluate differences in cognitive performance between individuals with and without insomnia, as well as potential interactions between insomnia and the APOE genotype. Voxel-based morphometry and tract-based spatial statistics were used to assess between-group differences and potential interactions between insomnia and the APOE genotype in gray matter volume and white matter diffusion metrics.
Insomnia was reported by 615 out of 1683 participants (36.5%), including 137 out of 366 (37.4%) with T1-weighted structural imaging available and 119 out of 334 (35.6%) with diffusion-weighted imaging. Individuals with insomnia (n = 615) performed worse in executive function tests than non-insomniacs and displayed lower gray matter volume in left orbitofrontal and right middle temporal cortex, bilateral precuneus, posterior cingulate cortex and thalamus, higher gray matter volume in the left caudate nucleus, and widespread reduction of mean and axial diffusivity in right hemisphere white matter tracts. Insomnia interacted with the APOE genotype, with APOE-ε4 carriers displaying lower gray matter volumes when insomnia was present, but higher volumes when insomnia was not present, in several gray matter regions, including the left angular gyrus, the bilateral superior frontal gyri, the thalami, and the right hippocampus.
Insomnia in cognitively unimpaired adults at increased risk for AD is associated to poorer performance in some executive functions and volume changes in cortical and subcortical gray matter, including key areas involved in Alzheimer's disease, as well as decreased white matter diffusivity.
Mexico ants Dáttilo, Wesley; Vásquez-Bolaños, Miguel; Ahuatzin, Diana A. ...
Ecology (Durham),
04/2020, Letnik:
101, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Mexico is one of the most biodiverse countries in the world, with an important proportion of endemism mainly because of the convergence of the Nearctic and Neotropical biogeographic regions, which ...generate great diversity and species turnover at different spatial scales. However, most of our knowledge of the Mexican ant biota is limited to a few well‐studied taxa, and we lack a comprehensive synthesis of ant biodiversity information. For instance, most of the knowledge available in the literature on Mexican ant fauna refers only to species lists by states, or is focused on only a few regions of the country, which prevents the study of several basic and applied aspects of ants, from diversity and distribution to conservation. Our aims in this data paper are therefore (1) to compile all the information available regarding ants across the Mexican territory, and (2) to identify major patterns in the gathered data set and geographic gaps in order to direct future sampling efforts. All records were obtained from raw data, including both unpublished and published information. After exhaustive filtering and updating information and synonyms, we compiled a total of 21,731 records for 887 ant species distributed throughout Mexico from 1894 to 2018. These records were concentrated mainly in the states of Chiapas (n = 6,902, 32.76%) and Veracruz de Ignacio de la Llave (n = 4,329, 19.92%), which together comprise half the records. The subfamily with the highest number of records was Myrmicinae (n = 10,458 records, 48.12%), followed by Formicinae (n = 3,284, 15.11%) and Ponerinae (n = 1,914, 8.8%). Most ant records were collected in the Neotropical region of the country (n = 12,646, 58.19%), followed by the Mexican transition zone (n = 5,237, 24.09%) and the Nearctic region (n = 3,848, 17.72%). Native species comprised 95.46% of the records (n = 20,745). To the best of our knowledge, this is the most complete data set available to date in the literature for the country. We hope that this compilation will encourage researchers to explore different aspects of the population and community research of ants at different spatial scales, and to aid in the establishment of conservation policies and actions. There are no copyright restrictions. Please cite this data paper when using its data for publications or teaching events.
Cancer of the head and neck comprises a group of neoplasms that share a similar anatomical origin. Most originate from the epithelium of the aerodigestive tract and 90% correspond to squamous cell ...carcinoma. In the last 15 years, an increase in the incidence of squamous cell carcinoma induced by human papillomavirus (HPV) has been seen, mainly types 16 and 18, which are the most frequent found in cancers of the oral cavity and oropharynx, and types 6 and 11 in laryngeal cancer. There are reports in the literature that show HPV as the leading cause of oropharyngeal squamous cell carcinoma.
Determine the prevalence of infection with high-risk HPV in patients diagnosed with squamous cell carcinoma of the oral cavity, oropharynx and larynx.
An observational, cross-sectional, descriptive, unblinded study was performed. Prevalence of HPV infection was determined by polymerase chain reaction (PCR) in DNA samples from tumour tissue of patients with squamous cell carcinoma of the oral cavity, oropharynx and larynx. Typing was subsequently performed in HPV positive samples in order to detect types 18, 16, 11 and 6, using custom primers.
A total of 45 patients were included. The association between laryngeal squamous cell carcinoma and HPV was established in two patients, which represented an overall prevalence of 4.4% in our population, and 10% for laringeal tumours.
There is a low prevalence of HPV infection in squamous cell carcinoma of the oral cavity, oropharynx and larynx, in our population. Prospective studies on younger patients could provide more information.
Sexual intercourse is currently the main route of HIV infection in Spain. Despite decreases in new infections among women and drug users, the rate remains stable in men. The aim of this study was to ...assess risk behaviour and HIV awareness in a sample of young adults in Spain.
A cross-sectional, observational, descriptive study was performed on a non-HIV infected sample, using a questionnaire on sexual health and HIV awareness adapted from the Spanish National Institute of Statistics. A sexual risk variable was included (high and low), which was classified as high if subjects had had three or more sexual partners and did not always use a condom in all their sexual encounters.
243 subjects were included (65.6% women) aged between 16 and 36 years (mean=25.7; SD=4.1) (16–24 years: 134 subjects; 25–29 years: 60 subjects; over 30years: 47 subjects). Approximately 40.9% said that they used a condom in all sexual relations and 61% did not perceive any risk of infection. There were no significant differences in awareness of infection routes between the high and low risk profiles. Washing after sex, having few partners, spermicide use and having undetectable viral load were protective measures significantly associated with differences in sexual risk (p<0.05).
The main finding of the study was the underestimation of risk of infection, analysed after differences found between self-assessment and sexual risk. Both positive and negative results were found concerning HIV awareness.
El contacto sexual es actualmente en España la primera vía de contagio de VIH. Pese a los descensos en el número de nuevas infecciones en mujeres y consumo de drogas, en hombres se mantiene estable. El presente estudio pretende evaluar conductas de riesgo y conocimientos sobre VIH en una muestra de jóvenes en España.
Se realizó un estudio observacional descriptivo transversal utilizando un cuestionario sobre salud sexual y conocimiento sobre el VIH adaptado del Instituto Nacional de Estadística. El grupo estuvo compuesto por jóvenes no infectados por VIH. Se incluyó la variable riesgo sexual (alto y bajo), siendo de riesgo alto los sujetos que habían tenido tres o más parejas y no utilizaban preservativo en todas las relaciones.
Se encuestaron 243 jóvenes (65,6% mujeres) de entre 16 y 36años (media=25,7; DE=4,1) (16-24años: 134 sujetos; 25-29años, 60 sujetos; más de 30años, 47 sujetos). El 40,9% contestaron que utilizaban el preservativo en todas sus relaciones y el 61% que no perciben ningún riesgo de infección. De forma mayoritaria no se encuentran diferencias significativas en conocimiento sobre vías de transmisión entre los grupos de alto y de bajo riesgo. Los métodos de protección que se asociaron significativamente con las diferencias en riesgo sexual fueron lavarse tras las relaciones sexuales, tener pocas parejas, uso de espermicidas y carga viral indetectable (p<0,05).
El principal resultado del estudio es la infravaloración personal de riesgo indicado según las diferencias encontradas entre la valoración personal y el índice de riesgo sexual. Se encuentran resultados tanto positivos como negativos en cuanto al conocimiento sobre el VIH.
Introduction: In 2014 the Consensus Document produced by the Spanish Paediatric Societies (SEIP-SERPE-SEOP) was published to help in the diagnosis and treatment of osteoarticular infections (OAI). In ...2015 the RIOPed was considered as a multidisciplinary national network for the investigation into OAI. The aim of this study was to assess the level of adaption to the recommendations established in the Consensus during one year of follow-up. Material and methods: A prospective, national multicentre study was carried out in 37 hospitals between September 2015 and September 2016. The study included patients >16 years-old with a diagnosis of OAI, confirmed by microbiological isolation, or probable: septic arthritis (SA) with >40,000 white cells in synovial fluid, or osteomyelitis (OM)/spondylodiscitis (SD) with a compatible imaging test. The results were compared with those obtained in a retrospective study conducted between 2008 and 2012. Results: A total of 235 cases were included, of which 131 were OM, 79 SA, 30 OA, and 15 SD. As regards the complementary tests that the Consensus considered mandatory to perform, radiography was carried out on 87.8% of the cases, a blood culture on 91.6%, and culture of the synovial fluid in 99% of SA. A magnetic resonance (MR) was performed on 71% of the OM cases. The choice of intravenous empirical antibiotic treatment was adapted to the recommendations in 65.1% of cases, and in 62.3% for the oral treatment. Surgery was performed in 36.8% of SA cases (85.7% arthrotomy), with a significant decrease compared to the retrospective study (P = .014). Only 58.5% of cases followed the recommendations on the duration of the treatment; however, a lower duration of intravenous treatment was observed. Conclusions: In general, the level of adaptation to the recommendations that were set by the Expert Group, is good for the complementary tests, and acceptable as regards the choice of antibiotic treatment, although inadequate in almost 40% of cases. A decrease in hospital stay was achieved. Resumen: Introducción: En 2014 se publicó el Documento de Consenso desarrollado por SEIP-SERPE-SEOP para el diagnóstico y el tratamiento de las infecciones osteoarticulares (IOA). En 2015 se constituyó RIOPed como red nacional multidisciplinar para la investigación en IOA. El objetivo del estudio ha sido valorar el grado de adecuación a las recomendaciones establecidas en el consenso durante un año de seguimiento. Material y métodos: Estudio prospectivo multicéntrico nacional realizado entre septiembre de 2015 y septiembre de 2016 en 37 hospitales con inclusión de pacientes menores de 16 años diagnosticados de IOA, confirmada mediante aislamiento microbiológico, o probable: artritis séptica (AS) con >40.000 leucocitos en líquido sinovial u osteomielitis (OM)/osteoartritis (OA)/espondilodiscitis (ED) con prueba de imagen compatible. Los resultados se compararon con los obtenidos en el estudio retrospectivo realizado entre 2008 y 2012. Resultados: Se incluyeron 255 casos: 131 OM, 79 AS, 30 OA y 15 ED. Respecto a las pruebas complementarias que el consenso consideró de obligada realización, la radiografía se llevó a cabo en el 87,8% de los casos, el hemocultivo en el 91,6% y el cultivo de líquido sinovial en el 99% de AS. Se realizó RM en el 71% de las OM. La elección del tratamiento antibiótico intravenoso empírico se adecuó a las recomendaciones en el 65,1% de los casos, y en el 62,3% para el tratamiento oral. Se llevó a cabo cirugía en el 36,8% de las AS (85,7% artrotomía), con un descenso significativo respecto al estudio retrospectivo (P = ,014). Solo el 58,5% de casos se ajustaron a las recomendaciones de duración del tratamiento; sin embargo, se comprobó una menor duración del tratamiento intravenoso. Conclusiones: En general, el grado de adecuación a las recomendaciones que marcaron el grupo de expertos es bueno para las pruebas complementarias y aceptable respecto a la elección del tratamiento antibiótico, aun detectándose casi un 40% de inadecuación. Se ha conseguido un descenso de la estancia hospitalaria.
Fundamento: la enseñanza del idioma inglés desempeña un importante papel en la formación de profesionales y técnicos de la salud. Objetivo: diseñar acciones metodológicas para el desarrollo de la ...habilidad escribir en el ciclo inglés con propósitos específicos, en ciencias médicas. Métodos: se realizó una investigación de desarrollo en la Universidad de Ciencias Médicas de Villa Clara, entre enero 2015 y diciembre 2016. Se emplearon métodos teóricos: histórico-lógico, analítico-sintético, inductivo-deductivo y sistémico-estructural, y como métodos empíricos, el análisis documental de los textos English Through Medicine 1 y 2; observación, entrevista a informantes clave, prueba pedagógica, y métodos estadístico-matemáticos. Resultados: los ejercicios en los libros de textos no contemplan la habilidad escribir como proceso, sino orientados al producto; se constataron insuficiencias en el conocimiento de los fundamentos metodológicos para desarrollarla en la mayoría de los profesores, y dificultades en los estudiantes para redactar textos, por lo que se diseñaron acciones metodológicas las que fueron valoradas por criterios de especialistas. Conclusiones: las acciones orientan adecuadamente hacia el buen desarrollo de la mencionada habilidad y tributan al objetivo final del egresado, fueron valoradas por los especialistas consultados como pertinentes, aplicables, con enfoque metodológico y con posibilidades de generalización debido a su concepción didáctica y estructura lógica.
El carcinoma de cabeza y cuello comprende un grupo de neoplasias que comparten un origen anatómico similar. La mayoría se originan de la mucosa del tracto aerodigestivo y más del 90% corresponden al ...carcinoma espinocelular. En los últimos 15 años se observó un incremento en la incidencia de carcinoma espinocelular inducido por el virus del papiloma humano (VPH) en jóvenes, principalmente los serotipos 16 y 18, los cuales son los más estudiados en cáncer de cavidad oral y orofaringe, y los serotipos 6 y 11 en cáncer de laringe. Existen reportes en la literatura sobre el VPH como principal causa de carcinoma espinocelular, principalmente de orofaringe.
Determinar la prevalencia de infección por VPH de alto riesgo en pacientes con diagnóstico de carcinoma espinocelular de cavidad oral, orofaringe y laringe.
Estudio observacional, transversal, descriptivo, no ciego. Se determinó la prevalencia de infección por VPH por medio de la reacción en cadena de la polimerasa en muestras de ADN de tejido tumoral en pacientes con carcinoma espinocelular de cavidad oral, orofaringe y laringe. Se realizó tipificación de serotipos de alto riesgo.
Se incluyó en el estudio un total de 45 pacientes. La asociación entre el carcinoma de células escamosas de laringe con VPH se ailo en 2 pacientes, lo cual represento una prevalencia global del 4.4% en nuestra población y del 10% para los tumores de laringe.
Existe una baja prevalencia de carcinoma espinocelular de la cavidad oral, orofaringe y laringe, asociado a infección por VPH en nuestra población. Estudios prospectivos en población más joven con cáncer de cabeza y cuello podrían aportar mayor información sobre la influencia del VPH en dicha patología.
Cancer of the head and neck comprises a group of neoplasms that share a similar anatomical origin. Most originate from the epithelium of the aerodigestive tract and 90% correspond to squamous cell carcinoma. In the last 15 years, an increase in the incidence of squamous cell carcinoma induced by human papillomavirus (HPV) has been seen, mainly types 16 and 18, which are the most frequent found in cancers of the oral cavity and oropharynx, and types 6 and 11 in laryngeal cancer. There are reports in the literature that show HPV as the leading cause of oropharyngeal squamous cell carcinoma.
Determine the prevalence of infection with high-risk HPV in patients diagnosed with squamous cell carcinoma of the oral cavity, oropharynx and larynx.
An observational, cross-sectional, descriptive, unblinded study was performed. Prevalence of HPV infection was determined by polymerase chain reaction (PCR) in DNA samples from tumour tissue of patients with squamous cell carcinoma of the oral cavity, oropharynx and larynx. Typing was subsequently performed in HPV positive samples in order to detect types 18, 16, 11 and 6, using custom primers.
A total of 45 patients were included. The association between laryngeal squamous cell carcinoma and HPV was established in two patients, which represented an overall prevalence of 4.4% in our population, and 10% for laringeal tumours.
There is a low prevalence of HPV infection in squamous cell carcinoma of the oral cavity, oropharynx and larynx, in our population. Prospective studies on younger patients could provide more information.
PDF
