Search results for "gea"

The endoscopic measurement of intravascular pressure and flow in oesophageal varices.

1988

Curative endoscopic therapy in patients with early esophageal squamous-cell carcinoma or high-grade intraepithelial neoplasia.

2007

Background and study aims Endoscopic resection of esophageal squamous-cell neoplasia with curative intent is considered to be a safe and effective alternative treatment to radical surgery in cases where the neoplasia is intraepithelial or limited to the mucosal layer. These patients are at risk for recurrent malignancy in the preserved esophagus, however. We conducted a prospective study to evaluate the efficacy and safety of endoscopic resection and to analyze variables associated with recurrence in patients with mucosal or intraepithelial squamous-cell neoplasia. Patients and methods Between December 1997 and September 2005, 65 patients (mean age +/- standard deviation [SD] 62.9 +/- 9.5 y…

Estudio de marcadores de enfermedad mínima residual en neuroblastoma y de su posible aplicación clínica

2016

El neuroblastoma es el tumor sólido extracraneal más frecuente en la infancia y el cuarto en frecuencia en el conjunto global de neoplasias infantiles. Su incidencia en nuestro país, según el RNTI oscila entre 8-10 casos por millón de niños y año, por lo que su frecuencia supone alrededor de un 8-10% de todos los tumores en niños. Sin embargo, es el responsable de aproximadamente un 15% del total de muertes provocadas por cáncer pediátrico. La edad media del diagnóstico es de 22 meses, dos tercios de los casos se presentan antes de los 5 años de edad y en un 97% los pacientes tienen menos de 10 años. El tumor es más común en niños que en niñas, siendo el ratio niño/niña aproximadamente 1,3/…

Modeling of Wind Turbine Gearbox Mounting

2011

In this paper three bushing models are evaluated to find a best practice in modeling the mounting of wind turbine gearboxes. Parameter identification on measurements has been used to determine the bushing parameters for dynamic simulation of a gearbox including main shaft. The stiffness of the main components of the gearbox has been calculated. The torsional stiffness of the main shaft, gearbox and the mounting of the gearbox are of same order of magnitude, and eigenfrequency analysis clearly reveals that the stiffness of the gearbox mounting is of importance when modeling full wind turbine drivetrains.

Landing gear suspension control through adaptive backstepping techniques with H∞ performance

2011

Author's version of a chapter published in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.00589

Design optimization on the drive train of a light-weight robotic arm

2011

A drive train optimization method for design of light-weight robots is proposed. Optimal selections of motors and gearboxes from a limited catalog of commercially available components are done simultaneously for all joints of a robotic arm. Characteristics of the motor and gearbox, including gear ratio, gear inertia, motor inertia, and gear efficiency, are considered in the drive train modeling. A co-simulation method is developed for dynamic simulation of the arm. A design example is included to demonstrate the proposed design optimization method.

Finite Element Method Analysis of a Spur Gear with a Corrected Profile

2007

The difference between the stress value calculated by a two-dimensional finite element model of spur gears and those obtained by the rules in ISO 6336 was evaluated. Hertz theory, which provides information on the extension of the contact area and the maximum value of the contact pressure, was used to choose the dimensions of the elements. The mesh was created using the stress analytical solution relative to a model consisting of two cylinders in contact. Analogous optimization was executed for the mesh of the teeth feet; a mesh of 15 elements was considered optimum, because it minimized the difference to 0.5 per cent in the bending stress calculation. Stress values, obtained using the fin…

Using moss and lichens in biomonitoring of heavy-metal contamination of forest areas in southern and north-eastern Poland.

2017

Abstract In the years 2014–2016 biomonitoring studies were conducted in the forest areas of south and north-eastern Poland: the Karkonosze Mountains, the Beskidy Mountains, the Borecka Forest, the Knyszynska Forest and the Bialowieska Forest. This study used epigeic moss Pleurozium schreberi and epiphytic lichens Hypogymnia physodes. Samples were collected in spring, summer and autumn. Approximately 500 samples of moss and lichens were collected for the study. In the samples, Mn, Ni, Cu, Zn, Cd, Hg and Pb concentrations were determined. Based on the obtained results, the studied areas were ranked by extent of heavy-metal deposition: Beskidy > Karkonosze Mountains > forests of north-eastern …

Erythrocyte aggregation in nonvalvular atrial fibrillation

2001

Koinzidenz von Plattenepithelkarzinomen der Speiseröhre und Kopf-Hals-Karzinomen: Risiko und Früherkennung

2007

Patients suffering from head and neck cancer (HNC) have or will develop a second esophageal squamous cell cancer (ESCC) in 5 - 14 %. When a second esophageal neoplasm occurs in a HNC patient, the prognosis is generally determined by the ESCC, and unfortunately it is poor. Prospective clinical studies in Japan, Brazil, Taiwan, France and Germany have shown that screening or surveillance using Lugol chromoesophagoscopy enables early detection of second esophageal neoplasias. Such a surveillance results in a survival benefit for HNC patients. Vice versa, ESCC patients also have a risk of 9.3 - 11.4 % for a head and neck cancer. Periodic otolaryngeal examination and pharyngoscopy is recommended…