Tuning the exponential sensitivity of a bound-state-in-continuum optical sensor.

In this work, we investigate the evanescent field sensing mechanism provided by an all-dielectric metasurface supporting bound states in the continuum (BICs). The metasurface is based on a transparent photonic crystal with subwavelength thickness. The BIC electromagnetic field is localized along the direction normal to the photonic crystal nanoscale-thin slab (PhCS) because of a topology-induced confinement, exponentially decaying in the material to detect. On the other hand, it is totally delocalized in the PhCS plane, which favors versatile and multiplexing sensing schemes. Liquids with different refractive indices, ranging from 1.33 to 1.45, are infiltrated in a microfluidic chamber bonded to the sensing dielectric metasurface. We observe an experimental exponential sensitivity leading to differential values as large as 226 nm/RIU with excellent FOM. This behavior is explained in terms of the physical superposition of the field with the material under investigation and supported by a thorough numerical analysis. The mechanism is then translated to the case of molecular adsorption where a suitable theoretical engineering of the optical structure points out potential sensitivities as large as 4000 nm/RIU

Effects of Alzheimer’s Disease on Visual Target Detection: A “Peripheral Bias”

Visual exploration is an omnipresent activity in everyday life, and might represent an important determinant of visual attention deficits in patients with Alzheimer’s Disease (AD). The present study aimed at investigating visual search performance in AD patients, in particular target detection in the far periphery, in daily living scenes. Eighteen AD patients and 20 healthy controls participated in the study. They were asked to freely explore a hemispherical screen, covering ±90°, and to respond to targets presented at 10°, 30°, and 50° eccentricity, while their eye movements were recorded. Compared to healthy controls, AD patients recognized less targets appearing in the center. No difference was found in target detection in the periphery. This pattern was confirmed by the fixation distribution analysis. These results show a neglect for the central part of the visual field for AD patients and provide new insights by mean of a search task involving a larger field of view

Effects of age and eccentricity on visual target detection

The aim of this study was to examine the effects of aging and target eccentricity on a visual search task comprising 30 images of everyday life projected into a hemisphere, realizing a ±90° visual field. The task performed binocularly allowed participants to freely move their eyes to scan images for an appearing target or distractor stimulus (presented at 10°; 30°, and 50° eccentricity). The distractor stimulus required no response, while the target stimulus required acknowledgment by pressing the response button. One hundred and seventeen healthy subjects (mean age = 49.63 years, SD = 17.40 years, age range 20–78 years) were studied. The results show that target detection performance decreases with age as well as with increasing eccentricity, especially for older subjects. Reaction time also increases with age and eccentricity, but in contrast to target detection, there is no interaction between age and eccentricity. Eye movement analysis showed that younger subjects exhibited a passive search strategy while older subjects exhibited an active search strategy probably as a compensation for their reduced peripheral detection performance

BRSMG 780Frr: cultivar de soja transgênica.

A brsmg 780rr é sua nova opção em soja transgênica para o manejo da ferrugem asiática. Alta produtividade e resistência moderada à ferrugem asiática. Grupo de maturidade. Regiões edafoclimáticas de adaptação (REC 303 - MG Triângulo Mineiro e Alto Paranaíba). Reação a doenças. Características médias. População de plantas e ciclo em solos férteis. Manejo da ferrugem asiática.bitstream/item/57490/1/BRSMG780Frr.pdf1 folder

Effects of Usnic Acid on Hyperglycemia and Renal Function in Streptozotocin-Induced Diabetic Rats

Background: Diabetic hyperglycemia and glomerular hyper filtration play a causative role in the progression of chronic kidney disease. Renal glucose handling via Sodium-Glucose Cotransporter (SGLT)-2 is a targetable approach and SGLT-2 inhibitors have proven therapeutic benefits in diabetic kidney disease. Usnic Acid (UA) is an active constituent of lichen species and symbiotic organism of algae and fungi, which is variously studied in folk medicine. The objective of this study was to demonstrate the beneficial effects of UA on glucose homeostasis and renal function in streptozotocin-induced diabetic Sprague-Dawley rats and to determine whether UA has an effect on regulation of SGLT that may further aid in glucoregulation and renal function. Methods: Type 1 diabetes was induced in Sprague-Dawley rats with Streptozotocin (STZ, 60mg/kg) by intraperitoneal route on day 0. Diabetic rats were treated with UA (75 mg/kg) from day 15 to 35 via oral gavage. On day 35, urine was collected and Oral Glucose Tolerance Test (OGTT) was performed. After OGTT, blood was collected through cardiac puncture and kidneys were preserved for biochemical analysis. The results are expressed as mean ± standard error of the mean for n=8 rats per study group. The data were subjected to 1-way or 2-way ANOVA with Bonferroni’s multiple comparison post hoc test using Graph Pad Prism 5 and were considered significant at p≤0.05. Results: Diabetic rats chronically treated with UA had improved hyperphagia, hyperglycemia and glucose intolerance, glomerular hyper filtration, and urinary protein excretion (p\u3c0.05). However, UA did not prevent loss of circulating insulin in diabetic rats. UA’s blood glucose lowering effect was associated with enhanced diuretic-glucosuric response and decreased protein expression of renal SGLT-1 (p\u3c0.05). While protein expression of SGLT-2 was partially increased in the diabetic kidney and it was not decreased by UA. Metabolic corrections with UA treatment occurred in parallel with reductions in uremia and improvement of renal function indices. Additionally, in diabetic rat kidney, UA treatment corrected oxidative changes. Conclusions: Based on preliminary findings we conclude that chronic treatment of UA may act in an insulin-independent manner in lowering of diabetic hyperglycemia and improvement of renal function

Influência do tamanho da semente na qualidade fisiológica e na produtividade da cultura da soja.

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Eficiência de bio e imunoensaio para detecção de semente de soja geneticamente modificada tolerante ao glifosato em lotes de sementes de soja não transgênica.

A produção de semente de soja livre de sementes de outras cultivares ou outras sementes, dentro dos limites estabelecidos pela legislação, é facilitada pelo fato da soja ser espécie autógama. No caso específico das cultivares geneticamente modificadas (GM), a baixa taxa de fecundação cruzada que ainda pode existir é um dos pontos críticos de contaminação genética dos campos de sementes convencionais por transgênicos. O objetivo deste trabalho foi verificar a eficiência de dois métodos de detecção de misturas de semente GM em amostras de soja convencional, para avaliar lotes de sementes quanto aos limites exigidos pela legislação. Foram utilizadas amostras de semente da cultivar BRSMG 810C (convencional) e da cultivar BRSMG 850GRR. Foram avaliados dois tamanhos de amostras (200 e 400 sementes), com quatro níveis de contaminação (semente GM adicionada às amostras convencionais, para se obter 0%, 0,5%, 1% e 1,5%), e dois métodos de detecção: imunoensaio de fluxo lateral e bioensaio (pré-embebição em solução de herbicida a 0,6% do equivalente ácido, na proporção de 2,5 vezes o peso do substrato, por 16 horas no escuro a 25oC). O método de bioensaio é eficiente na detecção da presença de GM em amostras de semente convencional de soja, desde que as mesmas apresentem alta qualidade fisiológica. Existe correlação significativa entre os valores obtidos pelo método de detecção por bioensaio e os níveis de contaminação estabelecidos (r= 0,82; p< ou = 0,0001). O tamanho da amostra não influenciou a eficiência dos dois métodos na detecção da presença de sementes adventícias (GM)