Search results for " nuclear"
showing 10 items of 11776 documents
Aplicaciones de la Resonancia Magnética Nuclear en el estudio de la Infertilidad
2015
En los últimos años se ha producido una reducción en el número de nacimientos en muchos países, fundamentalmente europeos. Esta reducción puede ser debida a diversos factores que afecten a la fertilidad de la mujer tales como factores culturales, sociales y económicos que aumentan la edad de la mujer para concebir su primer hijo, causas inmunitarias, alteraciones del aparato reproductor femenino, causas hipotalámico-hipofisarias y factores relacionados con el estilo de vida entre otros. Estos problemas de fertilidad se pueden solucionar mediante diversos tratamientos de reproducción asistida, como la inseminación artificial o la fecundación in vitro. En estos últimos, el ovocito que se empl…
Characterization of the metabolic profile and identification of potential therapeutic targets in advanced prostate cancer patients
2023
INTRODUCCIÓN El cáncer de próstata (CaP) representa el segundo tumor en incidencia en hombres y es la quinta causa de muerte por cáncer a nivel global. El CaP es un tumor hormono-dependiente, que requiere de la activación del receptor de andrógenos (AR) para su proliferación. Clínicamente, se caracteriza por una gran variabilidad en su evolución, progresando desde una condición indolente hasta un fenotipo agresivo que puede diseminarse y metastatizar a los nodos linfáticos y huesos. Actualmente, el diagnóstico temprano del CaP se realiza mediante la determinación sérica del antígeno prostático específico (PSA) y el examen rectal digital (DRE). Si estas pruebas dan resultados anómalos y hay …
Evaluación morfológica y morfométrica de neuroimágenes retinianas y cerebrales como factor pronóstico de la función visual en pacientes con esclerosi…
2013
El propósito de esta tesis doctoral es estudiar la proporción de pérdida neurológica en el tiempo a nivel cerebral y retiniano en relación con la deficiencia sensorial y motora en pacientes diagnosticados de esclerosis múltiple. La muestra está constituida por 35 pacientes clasificados en tres grupos en función del subtipo de enfermedad (síndromes clínicos aislados, formas remitentes-recurrentes y formas progresivas) diagnosticados de esclerosis múltiple según los criterios de McDonald, aunque a efectos del análisis estadístico, las unidades de observación fueron los 70 ojos correspondientes. Se recopiló información mediante la anamnesis y revisión de la historia clínica de los pacientes re…
Macular Structure–Function Relationships of All Retinal Layers in Primary Open-Angle Glaucoma Assessed by Microperimetry and 8 × 8 Posterior Pole Ana…
2021
Purpose: The aim of this study is too correlate the sensitivity and thickness values of intraretinal layers at macula in healthy eyes and primary open-angle glaucoma (POAG) eyes. Methods: The thickness of different intraretinal segmentations was estimated by means of optical coherence tomography (OCT) Spectralis (Heidelberg, Engineering, Inc., Heidelberg, Germany) with the posterior pole analysis program 8 × 8 in 91 eyes from 91 patients (60 with glaucoma and 31 healthy patients). Macular sensitivity was also measured with an MP-1 microperimeter (Nidek Instruments, Inc Padova, Italy) with a customized, 36-stimulus pattern adjusted to an anatomical correspondence with the OCT grid. Correlati…
FMECA Application in Tomotherapy: Comparison between Classic and Fuzzy Methodologies
2022
Accident analysis in radiotherapy highlighted the need to increase quality assurance (QA) programs by the identification of failures/errors with very low probability (rare event) but very severe consequences. In this field, a Failure Mode, Effects and Criticality Analysis (FMECA) technique, used in various industrial processes to rank critical events, has been met with much interest. The literature describes different FMECA methods; however, it is necessary to understand if these tools are incisive and effective in the healthcare sector. In this work, comparisons of FMECA methodologies in the risk assessment of patients undergoing treatments performed with helical tomotherapy are reported. …
Methyl 3',4',5'-trimethoxybiphenyl-4-carboxylate
2013
In the title compound, C17H18O5, the dihedral angle between the benzene rings is 31.23 (16)°. In the crystal, the molecules are packed in an antiparallel fashion in layers along the a axis. In each layer, very weak C-H...O hydrogen bonds occur between the methoxy and methyl ester groups. Weak C-H...[pi] interactions between the 4'- and 5'-methoxy groups and neighbouring benzene rings [methoxy-C-ring centroid distances = 4.075 and 3.486 Å, respectively] connect the layers.
Beta-decay studies for applied and basic nuclear physics
2020
In this review we will present the results of recent beta-decay studies using the total absorption technique that cover topics of interest for applications, nuclear structure and astrophysics. The decays studied were selected primarily because they have a large impact on the prediction of a) the decay heat in reactors, important for the safety of present and future reactors and b) the reactor electron antineutrino spectrum, of interest for particle/nuclear physics and reactor monitoring. For these studies the total absorption technique was chosen, since it is the only method that allows one to obtain beta decay probabilities free from a systematic error called the Pandemonium effect. The me…
Ultrasound bioeffects in rats: quantification of cellular damage in the fetal liver after pulsed Doppler imaging
2011
Objective To determine whether pulsed Doppler examination of the ductus venosus in rat fetuses could damage exposed tissue. Methods On gestational day 18, the livers of a mean of approximately five fetuses per mother (n = 5.14, SD = 1.6), in a cohort of 35 pregnant female rats, were exposed individually to pulsed Doppler and these were considered the 'exposed group'. The remaining fetuses in each pregnant rat (n = 5.16, SD = 2.1) formed the 'control group'. We tested for 600, 300, 60, 20, 15, 10 and 3 s of exposure of the fetal ductus venosus and the damage was evaluated measuring a cell death index of apoptotic activity at 7 h post-exposure (n = 16). In addition, subgroups of mothers were …
Intravenous Contrast Material for Cardiac Computed Tomography
2023
Purpose: The Italian Registry of Contrast Material use in Cardiac Computed Tomography (iRCM-CCT) is a multicenter, multivendor, observational study on the use of contrast media (CM) in patients undergoing cardiac computed tomography (CCT). The aim of iRCM-CCT is to assess image quality and safety profile of intravenous CM compounds. Materials and methods: iRCM-CCT enrolled 1842 consecutive patients undergoing CCT (≥50 per site) at 20 cluster sites with the indication of suspected coronary artery disease. Demographic characteristics, CCT, and CM protocols, clinical indications, safety markers, radiation dose reports, qualitative (ie, poor vascular enhancement) and quantitative (ie, HU attenu…
An International Survey of Quality and Safety Programs in Radiology
2021
Purpose: The aim of this study was to determine the status of radiology quality improvement programs in a variety of selected nations worldwide. Methods: A survey was developed by select members of the International Economics Committee of the American College of Radiology on quality programs and was distributed to committee members. Members responded on behalf of their country. The 51-question survey asked about 12 different quality initiatives which were grouped into 4 themes: departments, users, equipment, and outcomes. Respondents reported whether a designated type of quality initiative was used in their country and answered subsequent questions further characterizing it. Results: The re…