1,508 research outputs found

    Skin tests and challenge-based drug allergy diagnosis: a retrospective study of patients with confirmed drug allergy

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    Objectives. To describe clinical manifestations and performed diagnostic workup, focusing drug challenge tests (DCT), in patients with drug allergy. Methods. Retrospective study including all patients with skin tests (STs) or DCT-based drug allergy diagnosis, between 01/2014 - 06/2018 in a Portuguese allergy unit. Data were collected from electronic and paper-based clinical records. Results. We had 75 drug allergy diagnoses. Most index reactions were mild and major or equal 1 hour after drug intake. 59 (78%) diagnoses were based on DCTs, all based on multistep protocols with major or equal 3 predicted steps. Only 10% of the DCT were positive during up-dosing; timing and severity of the index reaction predicted DCT interruption during up-dosing. Conclusions. Most drug allergy diagnoses were based on multistep DCT. The identified predictors of DCT interruption during up-dosing can support the development of more personalized DCTs protocols.info:eu-repo/semantics/publishedVersio

    Cost-Effectiveness of Different Diagnostic Strategies in Suspected Stable Coronary Artery Disease in Portugal

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    BACKGROUND: Cost-effectiveness is an increasingly important factor in the choice of a test or therapy. OBJECTIVE: To assess the cost-effectiveness of various methods routinely used for the diagnosis of stable coronary disease in Portugal. METHODS: Seven diagnostic strategies were assessed. The cost-effectiveness of each strategy was defined as the cost per correct diagnosis (inclusion or exclusion of obstructive coronary artery disease) in a symptomatic patient. The cost and effectiveness of each method were assessed using Bayesian inference and decision-making tree analyses, with the pretest likelihood of disease ranging from 10% to 90%. RESULTS: The cost-effectiveness of diagnostic strategies was strongly dependent on the pretest likelihood of disease. In patients with a pretest likelihood of disease of ≤50%, the diagnostic algorithms, which include cardiac computed tomography angiography, were the most cost-effective. In these patients, depending on the pretest likelihood of disease and the willingness to pay for an additional correct diagnosis, computed tomography angiography may be used as a frontline test or reserved for patients with positive/inconclusive ergometric test results or a calcium score of >0. In patients with a pretest likelihood of disease of ≥ 60%, up-front invasive coronary angiography appears to be the most cost-effective strategy. CONCLUSIONS: Diagnostic algorithms that include cardiac computed tomography angiography are the most cost-effective in symptomatic patients with suspected stable coronary artery disease and a pretest likelihood of disease of ≤50%. In high-risk patients (pretest likelihood of disease ≥ 60%), up-front invasive coronary angiography appears to be the most cost-effective strategy. In all pretest likelihoods of disease, strategies based on ischemia appear to be more expensive and less effective compared with those based on anatomical tests.info:eu-repo/semantics/publishedVersio

    Environmental memory boosts group formation of clueless individuals

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    The formation of groups of interacting individuals improves performance and fitness in many decentralised systems, from micro-organisms to social insects, from robotic swarms to artificial intelligence algorithms. Often, group formation and high-level coordination in these systems emerge from individuals with limited information-processing capabilities implementing low-level rules of communication to signal to each other. Here, we show that, even in a community of clueless individuals incapable of processing information and communicating, a dynamic environment can coordinate group formation by transiently storing memory of the earlier passage of individuals. Our results identify a new mechanism of indirect coordination via shared memory that is primarily promoted and reinforced by dynamic environmental factors, thus overshadowing the need for any form of explicit signalling between individuals. We expect this pathway to group formation to be relevant for understanding and controlling self-organisation and collective decision making in both living and artificial active matter in real-life environments

    The role of disorder in the motion of chiral swimmers in the presence of obstacles

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    The presence of obstacles is intuitively expected to hinder the diffusive transport of micro-swimmers. However, for chiral micro-swimmers, a low density of obstacles near a surface can enhance their diffusive behavior, due to the rectification of the chiral motion by the obstacles. Here, we study numerically the role that disorder plays in determining the transport dynamics of chiral micro-swimmers on surfaces with obstacles. We consider different densities of regularly spaced obstacles and distinct types of disorder: noise in the dynamics of the micro-swimmer, quenched noise in the positions of the obstacles as well as obstacle size polydispersity. We show that, depending on the type and strength of the disorder, the presence of obstacles can either enhance or hinder transport, and discuss implications for the control of active transport in disordered media

    The role of disorder in the motion of chiral active particles in the presence of obstacles

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    The presence of obstacles is intuitively expected to hinder the diffusive transport of active particles. However, for chiral active particles, a low density of obstacles near a surface can enhance their diffusive behavior. Here, we study numerically the role that disorder plays in determining the transport dynamics of chiral active particles on surfaces with obstacles. We consider different densities of regularly spaced obstacles and distinct types of disorder: noise in the dynamics of the particle, quenched noise in the positions of the obstacles as well as obstacle size polydispersity. We show that, depending on the type and strength of the disorder, the presence of obstacles can either enhance or hinder transport, and discuss implications for the control of active transport in disordered media

    Divergent trophic responses to biogeographic and environmental gradients

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    Following environmental changes, communities disassemble and reassemble in seemingly unpredictable ways. Whether species respond to such changes individualistically or collectively (e.g. as functional groups) is still unclear. To address this question, we used an extensive new dataset for the lake communities in the Azores' archipelago to test whether: 1) individual species respond concordantly within trophic groups; 2) trophic groups respond concordantly to biogeographic and environmental gradients. Spatial concordance in individual species distributions within trophic groups was always greater than expected by chance. In contrast, trophic groups varied non-concordantly along biogeographic and environmental gradients revealing idiosyncratic responses to them. Whether communities respond individualistically to environmental gradients thus depends on the functional resolution of the data. Our study challenges the view that modelling environmental change effects on biodiversity always requires an individualist approach. Instead, it finds support for the longstanding idea that communities might be modelled as a cohort if the functional resolution is appropriate

    Evaluación de gramíneas y leguminosas forrajeras como coberturas y su influencia en el control de malezas en el establecimiento de cítricos en el piedemonte del Meta.

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    In order to develop sustainable management systems for growing citrus in the tropics, the behavior of two species of legumes and four grasses were evaluated and compared with mechanical and chemical control in high terrace conditions of the Meta piedmont. The trial was established Desmodium ovalifolium cv. Maquenque, Paspalum notatum, Brachiaria dictyoneura cv. Llanero, Arachis pintoi CIAT 18744, Brachiaria brizantha cv. Toledo, Panicum maximum CIAT 36000, and the controls herbicide, brushcutter + herbicide. Experimental located on the streets of the Valencia orange orchard in Corpoica’s La Libertad research center in Villavicencio. The following variables were evaluated: the percentage of coverage and biomass production for two years, and resistance to penetration (RP) at the end of the experiment. To analyze the results, descriptive statistics, analysis of variance, and comparison using the least significant difference (LSD) were applied. The highest percentages of land cover on average were A. pintoi, P. maximum, and B. dictyoneura, with 96.98%, 95.98% and 94.5% land cover, respectively. In the 753 days after the test began, we found that P. maximum had produced 20,053 kg ha-1 of dry matter, followed by B. brizantha with 13,624 kg ha-1, which exceeded all other treatments statistically. However, A. pintoi was the species that generated the least RP, followed by D. ovalifolium. The results obtained show advantages in the use of coverage in the establishment phase of citrus such as weed control, reduced resistance to penetration, and the protection of soil from erosion by runoff.  Con el propósito de desarrollar sistemas de manejo sostenible para el cultivo de cítricos en el trópico bajo, se evaluó el comportamiento de dos especies de leguminosas y cuatro gramíneas en comparación con el control mecánico y químico, en condiciones de terraza alta del Piedemonte del meta. se establecieron las especies Desmodium ovalifolium cv. Maquenque, Paspalum notatum, Brachiaria dictyoneura cv. Llanero, Arachis pintoi CIAT 18744, Brachiaria brizantha cv. Toledo y Panicum maximum CIAT 36000, y los controles herbicida, guadaña + herbicida. El área experimental se estableció en las calles de un cultivo de naranja Valencia del Centro Investigación La Libertad de Corpoica en Villavicencio. Se evaluaron las variables porcentaje de cobertura y producción de biomasa durante dos años, y resistencia a la penetración (RP) al finalizar el experimento. Para el análisis de los resultados se utilizó estadística descriptiva, análisis de varianza y comparación de medias con la diferencia mínima significativa (DMS). Los mayores porcentajes de cobertura del suelo se obtuvieron con A. pintoi, P. maximun y B. dictyoneura, con 96,98%; 95,98% y 94,5%, respectivamente. En los 753 días después de establecido el ensayo, se encontró que P. maximum, produjo 20.053 kg ha-1 de materia seca, seguido de B. brizantha con 13.624 kg ha-1, los cuales superaron estadísticamente a otros tratamientos. Por otro lado, A. pintoi fue la especie que generó la menor RP seguida de D. ovalifolium. Los resultados obtenidos señalan ventajas en el uso de coberturas en la fase de establecimiento del cultivo de cítricos en cuanto al control de malezas, disminución de la resistencia a la penetración y protección del suelo a la erosión por escorrentía.

    Doença Renal na Região Autónoma da Madeira: Experiência de Vinte e Sete Anos de Biópsias de Rim Nativo

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    Introduction: Renal biopsy plays an essential role either in the diagnosis or in the prognosis of patients with renal disease. In order to assess its epidemiology and evolution in Madeira Islands, we analysed twenty-seven years of native kidney biopsies. Methods: We performed a retrospective analysis of clinical records, including histological revision from 1986 to 2012, totalling 315 native kidney biopsies. They were assessed regarding the temporal evolution both for the quality/indications for renal biopsy and for the patterns of kidney disease. Results: A total of 315 native kidney biopsies were analysed. The patients’ mean age was of 40.8 ± 18.4 years and 50.5%(n = 159) were males. The most common indications for renal biopsy were nephrotic syndrome (36.2%, n = 114) and acute kidney injury (20.0%, n = 63). Among primary glomerular diseases (41.5%, n = 115) the most common were IgA nephropathy (26.1%, n = 30) and focal-segmental glomerulosclerosis (17.4%, n = 20) and among secondary glomerular diseases (31.4%, n = 87), lupus nephritis (51.7%, n = 45) and amyloidosis (20.7%, n = 18). Statistical analysis revealed significant correlation between gender and major pathological diagnosis (Fisher’s exact test, p <.01) and between indications for renal biopsy and major pathological diagnosis (χ2, p <.01). Regarding the temporal evolution, no statistically significant differences were found in the number of renal biopsies (χ2, p =.193), number of glomeruli per sample (Fisher’s exact test, p =.669), age (Kruskal-Wallis, p =.216), indications for renal biopsy (χ2, p =.106) or major pathological diagnosis groups (χ2,p =.649). However, considering the specific clinico-pathological diagnoses and their temporal variation, a statistically significant difference (Fisher’s exact test, p <.05) was found for lupus nephritis and membranous nephropathy with an increasing incidence and for amyloidosis with an opposite tendency. Discussion: The review of the native kidney biopsies from a population with particular characteristics, geographically isolated, such as those from Madeira Islands, showed parallel between epidemiological numbers referring to other European subpopulations, allowing simultaneously a comprehensive approach to our renal biopsy policies
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