369 research outputs found
Use of a-shapes for the measurement of 3D bubbles in fluidized beds from two-fluid model simulations
A geometrical technique based on shape construction was employed to reconstruct the simulated domain of 3D bubbles in a gas-solid fluidized bed, from two-fluid model (TFM) simulations. The Delaunay triangulation of the cloud of points that represent volume fraction iso-surfaces in transient TFM simulations was filtered by means of the so-called a-shapes, allowing a topologically accurate description of 3D bubbles within a fluidized bed. Consequently, individual 3D bubble properties such as size and velocity were measured. Simulated bubble characteristics were further compared to those measured on pseudo-2D bed facilities by image techniques in order to illustrate the effect of the bed geometry on the bubbling behavior under mimicked operational conditions
An Overview of Analytical Techniques Employed to Evidence Drug-DNA Interactions. Applications to the Design of Genosensors
Determinación y validación de las cuencas hidrográficas de la Isla de Gran Canaria (Islas Canarias, España)
En el presente trabajo se plantea una metodología para la obtención y validación de dos elementos fundamentales en cualquier aplicación SIG hidrológica, que son las cuencas hidrográficas y los cursos de aguas o redes de drenaje (thalwegs). Como bien es sabido en la cartografía oficial a cualquier escala se definen los thalwegs, pero no así las cuencas hidrográficas, las cuales se pueden llegar a definir con la ayuda de un MDE (Modelo Digital de Elevaciones). A través de procesos automáticos en un SIG, se definen las cuencas hidrográficas. Se ha de evaluar la precisión de las mismas en función del paso de malla elegido en el MDE. Y de igual forma, se validan los thalwegs de la cartografía, ya que estos pueden poseer errores de posicionamiento.Peer ReviewedPostprint (published version
PET and CT image registration of the rat brain and skull using the air algorithm
Proceeding of: 2000 IEEE Nuclear Science Symposium Conference Record, Lyon, France, October 15 - 20, 2000Spatially registered PET and CT images of the same small animal offer at .least three potential advantages .over PET alone. First, the CT images should' alIow accurate, nearly noise-free correction of the PET image data for attenuation.
Second, the CT images snould permit more certain identification of structures evident in the PET images and third, the CT images provide a priori anatomical information
that may be of use with resolution-improving image reconstruction algorithms that model the PET imaging process. Thus far, howeyer, image registration algorithms effective in human studies have not been characterized in the small animal setting. Accordingly,'we evaluated the ability of the AIR algorithm to accurately register PET F-18 fluoride
and F-18 FDG images of the rat skull and brain, respectively, to CT images acquired following each PET imaging session.
The AIR algorithm was able to register the bone-to-bone images with a maximum error of less than 1.0 mm. The registration error for the brain-to-brain study, however, was
greater (2.4 mm) and required additional steps and. user.intervention to segment the brail1 from the head in both data
sets before registration. These preliminary results suggest that the AIR algorithm can accurately combine PET and CT images in small animals when the data sets are nearly
homologous, but may require additional segmentation steps with increased mis-registration errors when registering
disparate, low contrast soft tissue structures
Software architecture for multi-bed FDK-based reconstruction in X-ray CT scanners
Most small-animal X-ray computed tomography (CT) scanners are based on cone-beam geometry with a flat-panel detector orbiting in a circular trajectory. Image reconstruction in these systems is usually performed by approximate methods based on the algorithm proposed by Feldkamp et al. (FDK). Besides the implementation of the reconstruction algorithm itself, in order to design a real system it is necessary to take into account numerous issues so as to obtain the best quality images from the acquired data. This work presents a comprehensive, novel software architecture for small-animal CT scanners based on cone-beam geometry with circular scanning trajectory. The proposed architecture covers all the steps from the system calibration to the volume reconstruction and conversion into Hounsfield units. It includes an efficient implementation of an FDK-based reconstruction algorithm that takes advantage of system symmetries and allows for parallel reconstruction using a multiprocessor computer. Strategies for calibration and artifact correction are discussed to justify the strategies adopted. New procedures for multi-bed misalignment, beam-hardening, and
Housfield units calibration are proposed. Experiments with phantoms and real data showed the suitability of the proposed software architecture for an X-ray small animal CT based on
cone-beam geometry.This work was partially funded by AMIT project from the CDTI CENIT program, TEC2007-64731, TEC2008-06715- C02-01, RD07/0014/2009, TRA2009 0175, RECAVA-RETIC, and RD09/0077/00087 (Ministerio de Ciencia e Inovación), and ARTEMIS S2009/DPI-1802 (Comunidad de Madrid).Publicad
Comunicación entre el personal sanitario y el paciente afásico
Comunicación oral presentada en la Segunda Conferencia Internacional de Comunicación en Salud, celebrada el 23 de octubre de 2015 en la Universidad Carlos III de MadridIntroducción: la afasia es la pérdida de capacidad de expresión debida a una lesión temporal o crónica de los centros temporales. Se calcula que en España hay unos 300.000 casos. Las limitaciones varían dependiendo del área dañada, viéndose afectada su capacidad para hablar, leer, escribir o comprender. Objetivos: Conocer los principales errores
que comete el personal sanitario al comunicarse con el paciente afásico. Mostrar alternativas de comunicación entre paciente y personal sanitario. Fomentar la comunicación interprofesional. Metodología: se realiza una búsqueda bibliográfica en las bases de datos Dialnet, Lilacs, Medline y Cuiden Plus con las palabras “comunicación” “paciente” “afasia” para artículos a texto completo publicados en los últimos diez años. Resultados: la búsqueda ofreció resultados,
que después proceso de selección se redujeron a cuatro artículos. Resultados: la bibliografía sobre la temática
del estudio es escasa, la mayoría de los estudios se centran en el ámbito logopédico. Los profesionales que a diario se relacionan conel paciente afásico, carecen de formación en habilidades comunicativas, consecuencia de esro es que nos enfrentamos a una comunicación personal-paciente ineficaz reflejada en frustración en ambos. Se evidencia la necesidad de futuras líneas de investigación sobre este tema, con el fin, de mejorar la calidad de vida del enfermo afásico; así como
fomentar el dialogo entre logopedas y el resto de profesionales sanitarios
Effects of D-003, a mixture of high-molecular-weight sugar cane wax acids, on lipid peroxidation markers in older individuals: A randomized, double-blind, placebo-controlled study
AbstractBackground: Aging is associated with increased lipid peroxidation (LP). D-003, a mixture of long-chain aliphatic primary acids purified from sugar cane wax, has been found to inhibit LP in experimental models and in healthy subjects.Objectives: The aim of this study was to assess the effects of D-003 on LP markers and the lipid profile of older individuals.Methods: This randomized, double-blind, placebo-controlled study was conducted at the Plaza Veterans' House, Havana City, Cuba. Male and female patients aged ≥60 years with total cholesterol values of <6.1 mmol/L were eligible for inclusion in the study. After a 3-week lead-in and baseline assessment period, patients were randomized to receive PO D-003 5 mg/d, D-003 10 mg/d, or placebo for 8 weeks. The effect on copper-induced LP of low-density lipoprotein (LDL) particles was the primary variable, and the effects on plasma total antioxidant status (TAS), plasma malondialdehyde (MDA) concentration, plasma antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities, and the lipid profile were secondary variables. A clinical examination was performed at each visit (baseline, weeks 4 and 8). A clinical examination, LP, and blood tests (lipid profile, hematologic, and blood biochemistry safety indicators) were performed at baseline and after 8 weeks of treatment. Compliance and adverse events (AEs) were assessed at weeks 4 and 8. A 2-tailed P < 0.05 was considered statistically significant for comparisons of both continuous and categoric variables.Results: Fifty-four patients aged ≥60 years were assessed for inclusion in the study, and 51 patients (40 women, 11 men; mean [SD] age, 67 [6] years) were included in the study. The lag phase of conjugated diene formation increased significantly and in a dose-dependent manner in the group treated with D-003 5 mg (24.7%; P < 0.01) and in the group treated with D-003 10 mg (29.3%; P < 0.01) compared with placebo. The maximal rate of conjugated diene propagation decreased significantly in the D-003 5- and 10-mg groups −22.7% and −25.8%, respectively; both, P < 0.05) compared with placebo. TAS increased significantly (17.7% and 23.0%, respectively; both, P < 0.01) in both active treatment groups compared with placebo. Plasma MDA concentration decreased significantly in the D-003 10-mg group (−28.6%; P < 0.05) but not in the D-003 5-mg group, compared with placebo. These changes were also significant compared with baseline. Antioxidant enzyme activities did not change in the active treatment groups compared with placebo or baseline. In the D-003 5- and 10-mg groups, significant decreases were found in LDL cholesterol concentration (−15.8% and −23.8%, respectively; both, P < 0.001) and total cholesterol concentration (−13.0% and −16.8%, both, P < 0.05) compared with placebo. High-density lipoprotein cholesterol concentration increased significantly in the D-003 5-mg group (5.7%; P < 0.05) and the D-003 10-mg group (18.2%; P < 0.001) compared with placebo. Changes in the lipid profile were also significant compared with baseline. In the placebo group, no variable changed significantly compared with baseline. D-003 was well tolerated at both dose levels, and no patient withdrew from the study. There were a total of 3 AEs reported: insomnia and acidity in 2 patients receiving placebo; and heartburn in 1 patient receiving D-003 5 mg.Conclusions: D-003 5 and 10 mg/d administered to these older individuals (aged ≥60 years) for 8 weeks inhibited LP of LDL and increased TAS in a dose-dependent manner, while plasma MDA concentration decreased in the patients receiving D-003 10 mg/d only. D-003 was well tolerated at both dose
Perrault syndrome with neurological features in a compound heterozygote for two TWNK mutations : Overlap of TWNK-related recessive disorders
Altres ajuts: This research was supported with cofounding from the European Regional Development Fund (ERDF), "A way to make Europe") (to IdC); S2017/BMD‑3721‑RAREGENOMICS‑CM from the Consejería de Educación e Investigación de la Comunidad de Madrid (to MAMP).Background: Perrault syndrome is a rare autosomal recessive disorder that is characterized by the association of sensorineural hearing impairment and ovarian dysgenesis in females, whereas males have only hearing impairment. In some cases, patients present with a diversity of neurological signs. To date, mutations in six genes are known to cause Perrault syndrome, but they do not explain all clinically-diagnosed cases. In addition, the number of reported cases and the spectra of mutations are still small to establish conclusive genotype-phenotype correlations. Methods: Affected siblings from family SH19, who presented with features that were suggestive of Perrault syndrome, were subjected to audiological, neurological and gynecological examination. The genetic study included genotyping and haplotype analysis for microsatellite markers close to the genes involved in Perrault syndrome, whole-exome sequencing, and Sanger sequencing of the coding region of the TWNK gene. Results: Three siblings from family SH19 shared similar clinical features: childhood-onset bilateral sensorineural hearing impairment, which progressed to profound deafness in the second decade of life; neurological signs (spinocerebellar ataxia, polyneuropathy), with onset in the fourth decade of life in the two females and at age 20 years in the male; gonadal dysfunction with early cessation of menses in the two females. The genetic study revealed two compound heterozygous pathogenic mutations in the TWNK gene in the three affected subjects: c.85C>T (p.Arg29∗), previously reported in a case of hepatocerebral syndrome; and a novel missense mutation, c.1886C>T (p.Ser629Phe). Mutations segregated in the family according to an autosomal recessive inheritance pattern. Conclusions: Our results further illustrate the utility of genetic testing as a tool to confirm a tentative clinical diagnosis of Perrault syndrome. Studies on genotype-phenotype correlation from the hitherto reported cases indicate that patients with Perrault syndrome caused by TWNK mutations will manifest neurological signs in adulthood. Molecular and clinical characterization of novel cases of recessive disorders caused by TWNK mutations is strongly needed to get further insight into the genotype-phenotype correlations of a phenotypic continuum encompassing Perrault syndrome, infantile-onset spinocerebellar ataxia, and hepatocerebral syndrome
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