Development of a Dynamic Goniometer with an Incremental Encoder

Angle dynamic measurements of body joints have become an important parameter to know for sportsmen, physicians and analysts of rehabilitation processes. The development of devices that allows those measurements turns out to be a hard work for biomedical engineers because during the acquisition process the mechanical system usually affects the natural joints movements. Digital goniometers have been constructed using different electronic principles, especially using resistance variations in potentiometers. In this paper we propose the construction of a dynamic goniometer with an incremental encoder using a mechanical transmission between a hinge and a pulley connected to an optical disk. The rotation is detected with an infrared led and a phototransistor. Calculations are done through a microcontroller and finally shown in real time using a liquid crystal display (LCD).La medición dinámica de los ángulos articulares se ha convertido en un parámetro fundamental para deportistas, médicos y analistas de los procesos de rehabilitación. El desarrollo de dispositivos para estas aplicaciones ha presentado retos importantes debido a la imposibilidad de implementar los sistemas mecánicos requeridos para la medición, sin afectar el movimiento natural de las articulaciones. Los goniómetros digitales se han construido a partir de diferentes principios electrónicos, particularmente basados en las variaciones resistivas de potenciómetros. Este trabajo muestra el desarrollo e implementación de un goniómetro dinámico basado en un encoder incremental con un sistema de transmisión mecánico entre una articulación de tipo bisagra y una polea conectada a un disco óptico. La rotación se detecta con un LED infrarrojo y un fototransistor. El cálculo del movimiento angular en la articulación se realiza con un microcontrolador. Finalmente los datos se muestran en tiempo real en una pantalla de cristal líquido (LCD)

Compuestos fenólicos bioactivos y ácidos orgánicos en la decocción de frutos y hojas de Schinus areira L.

Se investigaron decocciones de hojas y frutos de Schinus areira L. del noroeste de Argentina. Compuestos fenólicos y ácidos orgánicos se analizaron mediante HPLC. Capacidad antioxidante e inhibición de α-glucosidasa se determinaron in vitro. Se evaluó toxicidad general con Artemia salina. Los principales compuestos fenólicos fueron hiperósido y ácido 3 O-cafeoilquínico en hojas y ácido gálico y catequina en frutos. Los principales ácidos orgánicos cuantificados fueron málico en hojas y cítrico en frutos. Ácido shikímico, precursor del Tamiflu está presente en decocción de frutos con un contenido relativamente importante. La de hojas presenta una mayor riqueza en compuestos bioactivos con actividad antirradicalaria frente a DPPH●, O2●- y ●NO. Las hojas y frutos de S. areira tenían una actividad inhibidora de la α-glucosidasa comparable a la de hiperósido y acarbosa. La decocción de frutas no fue eco-tóxica, pero sí la de hojas que podría ser fuente de compuestos bioactivos con actividad farmacológica.Leaf and fruit decoctions of Schinus areira L. from northwest Argentina were investigated here. Phenolic compounds and organic acids were analyzed by HPLC. Antioxidant capacity and αglucosidase inhibition were determined by using in vitro tests. The general toxicity was assessed against Artemia salina nauplii. Hyperoside and 3 O-caffeoylquinic acid in leaf decoctions; gallic acid and catechin in fruit decoction were the major phenolic compounds. Malic and citric acids were the main organic acid quantified in the leaf and fruit decoctions, respectively. Fruit decoction had a relatively important content of shikimic acid, precursor of Tamiflu. Leaf decoction presents a greater richness in bioactive compounds with antiradical activity against DPPH●, O2●- and ●NO radicals. S. areira leaves and fruits had α-glucosidase inhibitory activity comparable to hyperoside and acarbose. Fruit decoction was not eco-toxic; leaf decoction showed significant eco-toxic activity and could be chosen for the search of other bioactive compounds with pharmacological activity.Fil: Celaya, Liliana Soledad. Universidad Nacional de Misiones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Molina, Ana C.. Universidad Nacional de Jujuy. Facultad de Ingeniería; ArgentinaFil: Gonzalez, Adriana M.. Universidad Nacional de Jujuy. Facultad de Ingeniería; ArgentinaFil: Villa, Walter Cosme. Universidad Nacional de Jujuy. Facultad de Ingeniería; ArgentinaFil: Silva, Luis R.. Universidad de Porto; PortugalFil: Viturro, Carmen Ines. Universidad Nacional de Jujuy. Facultad de Ingeniería; Argentin

Modeling Response Variables in Taguchi Design Parameters Using CART and Random Forest Based Systems

[EN] Taguchi parameter design is a quality approach to design better products and processes, less sensitive to changes of the environmental and productive conditions. Robustness against changes in factors affecting processes is the key concept. Some recent papers have used a two steps methodology to improve parameter design. The first step determines the objective function using Artificial Neural Networks (ANN) to predict the value of the response variable when factors are in some specific levels (different to those included in the experiments). The second step looks for the optimal parameter combination. Our proposal here is centered in improving the first of these two steps, and consists in the development of new systems to model the response variable, based in Classification and Regression Trees (CART) and in Random Forest (RF), as an alternative to ANN and with the aim of creating a more robust strategy.Villa M, A.; Carrión García, A.; San Matías Izquierdo, S. (2012). Modeling Response Variables in Taguchi Design Parameters Using CART and Random Forest Based Systems. Communications in Dependability and Quality Management. 15(4):5-15. http://hdl.handle.net/10251/59860S51515

Microvascular ischemia in hypertrophic cardiomyopathy:new insights from high-resolution combined quantification of perfusion and late gadolinium enhancement

BACKGROUND: Microvascular ischemia is one of the hallmarks of hypertrophic cardiomyopathy (HCM) and has been associated with poor outcome. However, myocardial fibrosis, seen on cardiovascular magnetic resonance (CMR) as late gadolinium enhancement (LGE), can be responsible for rest perfusion defects in up to 30 % of patients with HCM, potentially leading to an overestimation of the ischemic burden. We investigated the effect of left ventricle (LV) scar on the total LV ischemic burden using novel high-resolution perfusion analysis techniques in conjunction with LGE quantification. METHODS: 30 patients with HCM and unobstructed epicardial coronary arteries underwent CMR with Fermi constrained quantitative perfusion analysis on segmental and high-resolution data. The latter were corrected for the presence of fibrosis on a pixel-by-pixel basis. RESULTS: High-resolution quantification proved more sensitive for the detection of microvascular ischemia in comparison to segmental analysis. Areas of LGE were associated with significant reduction of myocardial perfusion reserve (MPR) leading to an overestimation of the total ischemic burden on non-corrected perfusion maps. Using a threshold MPR of 1.5, the presence of LGE caused an overestimation of the ischemic burden of 28 %. The ischemic burden was more severe in patients with fibrosis, also after correction of the perfusion maps, in keeping with more severe disease in this subgroup. CONCLUSIONS: LGE is an important confounder in the assessment of the ischemic burden in patients with HCM. High-resolution quantitative analysis with LGE correction enables the independent evaluation of microvascular ischemia and fibrosis and should be used when evaluating patients with HCM

Fluoride Content in Foods and Beverages From Mexico City Markets and Supermarkets

Background: Sources of fluoride exposure for Mexicans include foods, beverages, fluoridated salt, and naturally fluoridated water. There are no available data describing fluoride content of foods and beverages consumed in Mexico. Objective: To measure the content of fluoride in foods and beverages typically consumed and to compare their content to that of those from the United States and the United Kingdom. Methods: Foods and beverages reported as part of the Mexican Health and Nutrition Survey (n = 182) were purchased in the largest supermarket chains and local markets in Mexico City. Samples were analyzed for fluoride, at least in duplicate, using a modification of the hexamethyldisiloxane microdiffusion method. Value contents were compared to those from the US Department of Agriculture and UK fluoride content tables. Results: The food groups with the lowest and highest fluoride content were eggs (2.32 µg/100 g) and seafood (371 µg/100 g), respectively. When estimating the amount of fluoride per portion size, the lowest content corresponded to eggs and the highest to fast foods. Meats and sausages, cereals, fast food, sweets and cakes, fruits, dairy products, legumes, and seafood from Mexico presented higher fluoride contents than similar foods from the United States or the United Kingdom. Drinks and eggs from the United States exhibited the highest contents, while this was the case for pasta, soups, and vegetables from the United Kingdom. Conclusion: The majority of items analyzed contained higher fluoride contents than their US and UK counterparts. Data generated provide the first and largest table on fluoride content, which will be useful for future comparisons and estimations

A low-cost HPV immunochromatographic assay to detect high-grade cervical intraepithelial neoplasia

Objective To evaluate the reproducibility and accuracy of the HPV16/18-E6 test. Methods The study population was comprised of 448 women with a previously abnormal Pap who were referred to the Barretos Cancer Hospital (Brazil) for diagnosis and treatment. Two cervical samples were collected immediately before colposcopy, one for the hr-HPV-DNA test and cytology and the other for the HPV16/18-E6 test using high-affinity monoclonal antibodies (mAb). Women with a histologic diagnosis of cervical intraepithelial neoplasia grade 2 or 3 were considered to be positive cases. Different strategies using a combination of screening methods (HPV-DNA) and triage tests (cytology and HPV16/18-E6) were also examined and compared. Results The HPV16/18-E6 test exhibited a lower positivity rate compared with the HPV-DNA test (19.0% vs. 29.3%, p<0.001) and a moderate/high agreement (kappa = 0.68, 95% CI: 0.60-0.75). It also exhibited a significantly lower sensitivity for CIN2+ and CIN3+ detection compared to the HPV-DNA test and a significantly higher specificity. The HPV16/18-E6 test was no different from cytology in terms of sensitivity, but it exhibited a significantly higher specificity in comparison to ASCH+. A triage test after HPV-DNA detection using the HPV16/18-E6 test exhibited a significantly higher specificity compared with a triage test of ASCH+ to CIN2+ (91.8% vs. 87.4%, p = 0.04) and CIN3+ (88.6% vs. 84.0%, p = 0.05). Conclusion The HPV16/18-E6 test exhibited moderate/high agreement with the HPV-DNA test but lower sensitivity and higher specificity for the detection of CIN2+ and CIN3+. In addition, its performance was quite similar to cytology, but because of the structural design addressed for the detection of HPV16/18-E6 protein, the test can miss some CIN2/3+ lesions caused by other high-risk HPV types.Cancer Prevention Department, Center for the Researcher Support and Pathology Department of the Barretos Cancer Hospital. This study was supported by CNPq 573799/2008-3 and FAPESP 2008/57889-1info:eu-repo/semantics/publishedVersio