450 research outputs found
Evaluación Bidimensional y Tridimensional de la VÃa Aérea Superior
Indexación: Scopus; Scielo.The aim of this study was to validate and correlate the two-dimensional (2D) with the three-dimensional (3D) measures of the upper airway assessment. Lateral cephalograms and cone beam CT of 100 adult subjects were used to perform a 2D and 3D assessment of the upper airway. Spearman correlation coefficient was used to determine whether there was correlation between variables. Additionally, specificity, sensitivity, negative predictive value and positive predictive value was calculated for the 2D assessment of the upper airway. Correlation between all two and three dimensional variables was found. In the nasopharynx and oropharynx, a weak correlation (r <0.51) was found; in the oropharynx a moderate one (0.50 <r <0.76). The validity tests of the 2D assessment resulted in a 73% sensitivity, 45% specificity, 93% negative predictive value and 14% positive predictive value for the nasopharynx; 100% sensitivity, 51% specificity, 100% negative predictive value and 6% positive predictive value in the oropharynx and 100% sensitivity, 71% specificity, 100% negative predictive value and 13% positive predictive value in the hypopharynx. There is a weak correlation between the 2D and 3D assessment of the upper airway. However, the lateral cephalogram has a high sensitivity and high negative predictive value, therefore, an additional complementary examination would not be necessary if the 2D assessment of the upper airway throws a normal result.http://ref.scielo.org/mpkrn
Evaluation of two toothbrushes prescriptions on the removal of plaque in patients with fixed orthodontic appliances
Indexación: Web of Science; ScieloLa aparatologÃa empleada en los tratamientos de ortodoncia, favorece la retención de placa bacteriana y dificulta su eliminación por parte del paciente, aumentando el riesgo de desarrollar caries, manchas blancas y enfermedad periodontal. Diferentes cepillos dentales se han desarrollado para facilitar la mantención de una adecuada higiene oral en estos pacientes, sin embargo, se ha observado que los cepillos comunmente indicados (cepillo ortodóncico mas cepillo unipenacho), no siempre son bien manejados y difÃcilmente se usan ambos. El cepillo Cross Action Pro-Salud®, se ha presentado como una alternativa simple de usar y de transportar, por ser un único cepillo que combina las caracteristicas de los dos cepillos comunmente recomendados. Para evaluar la efectividad de este cepillo, en comparación con la prescripción convencional, se evaluaron 2 grupos, de 23 pacientes cada uno, portadores de aparatologÃa fija. Un grupo utilizó la prescripción habitual y un segundo grupo utilizó cepillo Cross Action Pro-Salud®, por un perÃodo de 45 dÃas. Los indices de higiene de O`leary, de placa en brackets y gingival modificado fueron registrados al inicio y 45 dÃas después del uso diario de los cepillos antes mencionados. Se utilizó test-t para comparar los resultados obtenidos y se determinó que se produjo una disminución significativa en los tres indices de higiene, no existiendo diferencias en los resultados obtenidos entre ambas prescripciones. El cepillo Oral-B Cross-Action Pro-Salud® es una alternativa recomendable, ya que permite eliminar efectivamente la placa bacteriana en pacientes ortodónticos, y al ser un único cepillo, facilita y acorta el tiempo de cepillado.Orthodontic fixed appliances include elements that allow the accumulation of bacterial plaque, making tooth brushing more difficult and increasing the risk of developing caries, white spot lesions, and periodontal disease. Several toothbrushes designs have been developed to facilitate oral hygiene in orthodontic patients; however, it has been observed that most patients do not take enough time to brush using adequately both commonly prescribed toothbrushes (Oral-B End-Tufted® and Oral-B Orthodontic® brushes). Oral B Cross Action Pro-Health® has been presented as an alternative, easier to use and to transport. To assess the effectiveness of Cross Action Pro-Health® versus commonly prescribed toothbrushes, two randomly assigned groups of 23 orthodontic patients each, were evaluated. One group of patients used commonly prescribed toothbrushes and the second group used Cross Action Pro-Health®. O`Leary, modified gingival and Bracket plaque index were measured before and 45 days after the daily use of the two mentioned toothbrushes prescriptions. T-test was used to detect statistically significant differences among the brushes for each index. The results demonstrated a significant reduction of the three indexes with the daily use of Cross Action Pro-Health® and no differences were found versus commonly used prescription. Orthodontic patients may benefit from the use of a single brush prescription (Cross Action Pro-Health®), because effective plaque removal can be achieved easier and faster.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-01072012000300002&nrm=is
Análisis multiescala de las comunidades de coral hermatÃpico del PacÃfico Central Mexicano
The Mexican Central Pacific is located in a zone of oceanographic transition between two biogeographic provinces with particular conditions that affect the associated fauna. The objective of this study was to evaluate the variation of hermatypic coral assemblages in this region and to determine their relationship with the heterogeneity of the benthonic habitat and spatial variables. A total of 156 transects were carried out at 41 sites in the years 2010 and 2011. The sampling effort returned 96.7% of the coral richness expected for the area, with a total of 15 species recorded. The results showed that richness, diversity and cover of corals varied only at the site and state scales. However, the composition and coverage of all coral species, as well as the benthonic habitat structure, differed significantly across the study scales (i.e. sites, zones and states). Canonical redundancy analysis showed that variation in the richness, diversity and assemblages of corals was explained by the cover of live corals, articulated calcareous algae, sandy substrate, sponges and fleshy macroalgae. This study suggests that local scale (i.e. site) variation in the coral assemblages of the Mexican Central Pacific is the result of the heterogeneity of the benthonic habitat, while geomorphological and oceanographic characteristics play a greater role at regional scale.El PacÃfico Central Mexicano se localiza en una zona de transición oceanográfica entre dos provincias biogeográficas con condiciones ambientales particulares que afectan la fauna asociada. El objetivo del estudio fue evaluar la variación de las comunidades de coral hermatÃpico de esta región y determinar su relación con la heterogeneidad del hábitat bentónico y variables espaciales. Se realizaron 156 transectos en 41 sitios en los años 2010 y 2011. El esfuerzo de muestreo representó el 96.7% de la riqueza de coral esperada para el área, con un total de 15 especies registradas. Los resultados mostraron que la riqueza, diversidad y cobertura de corales variaron sólo en las escalas de sitio y de estado. En cambio, la composición y cobertura de todas las especies de coral, asà como la estructura del hábitat bentónico, fueron significativamente diferentes en todas las escalas estudiadas (i.e. sitio, zona y estado). Los análisis de redundancia canónica mostraron que la variación de la riqueza, diversidad y de las comunidades de corales eran explicadas por la cobertura de coral vivo, algas calcáreas articuladas, sustrato arenoso, esponjas y macroalgas carnosas. Este trabajo sugiere que la variación de las comunidades de coral en el PacÃfico Central Mexicano a escala local (i.e. sitio) se debe a la heterogeneidad del hábitat bentónico, mientras que a escala regional, las caracterÃsticas geomorfológicas y oceanográficas desempeñan un papel más importante
Ensamblajes bacterianos asociados a especies de coral del PacÃfico central mexicano
The functional role of coral-associated bacteria and their contribution to coral health is still largely unknown. The first necessary step to address this gap in the knowledge is based on characterization of the microbial assemblage of the coral and the species-specific, temporal and spatial variation in its diversity. Branched corals (e.g., genus Pocillopora), are the main builders of coral reefs worldwide. This study evaluated the bacteria associated with the mucus and tissues of Pocillopora damicornis and Pocillopora verrucosa, as well as that of the seawater and surrounding sediments, in 6 sites of the Mexican Central Pacific during summer and winter seasons. The molecular techniques DGGE and RFLP were used with the 16S rDNA to assess the most abundant bacterial OTUs. The relationships between the bacterial-coral assemblage and environmental and spatial variables of the reef surroundings were also evaluated, using the multivariate analyses. Twenty different Operational Taxonomic Units (OTU) were obtained, with the highest number presented by the sediments. Specificity of bacterial groups was found for each coral species, as well as between the tissue and mucus of each species. The results showed that the bacterial dominant groups were similar between seasons, but these showed significant spatial variations among substrates within sites, as well as per substrate across all sites. The environmental variables that explained the variation of the dominant bacterial groups in corals and sea water were the coverages of fleshy macroalgae, live coral and sponge. In contrast, variation in the sediments was explained by the coverages of sand, rubble and rock.El papel funcional de las bacterias asociadas a corales y su contribución a la salud del coral es aún desconocido en gran medida. Es necesario que primero se caracterice el ensamblaje microbiano del coral y sus cambios en la diversidad a través de las especies de coral, el espacio y tiempo. Los corales ramificados (e.g., género Pocillopora) son los principales constructores arrecifales a nivel mundial. Este estudio evaluó la estructura bacteriana asociada al mucus y tejidos de Pocillopora damicornis y Pocillopora verrucosa, asà como del agua de mar y sedimentos circundantes en 6 sitios del PacÃfico central mexicano. Se emplearon las técnicas DGGE y RFLP del ADNr 16S para generar los perfiles de bandeo o evaluar la diversidad. Además, se evaluó la relación del ensamblaje bacteriano-coral con variables ambientales y espaciales del entorno arrecifal (de cada sitio), utilizando análisis multivariados. Se obtuvieron 20 Unidades Taxonómicas Operacionales (OTU) diferentes, siendo los sedimentos los que presentaron mayor número. Se encontró una especificidad de grupos bacterianos para cada especie de coral, asà como entre el tejido y mucus de cada especie. Los resultados mostraron que los grupos de bacterias dominantes variaron entre sustratos y entre sitios, encontrando, sólo una variación espacial significativa. Las variables ambientales que explican la variación de los grupos bacterianos dominantes en corales y agua de mar fueron las coberturas de macroalgas carnosas, coral vivo y esponja. En cambio, la variación en los sedimentos fue explicada por las coberturas de arena, escombro y roc
Estrés oxidativo e inflamación en insuficiencia cardiaca: Mecanismos de daño y alternativas terapéuticas
Setting upper limits on the strength of periodic gravitational waves from PSR J1939+2134 using the first science data from the GEO 600 and LIGO detectors
Data collected by the GEO 600 and LIGO interferometric gravitational wave detectors during their first observational science run were searched for continuous gravitational waves from the pulsar J1939+2134 at twice its rotation frequency. Two independent analysis methods were used and are demonstrated in this paper: a frequency domain method and a time domain method. Both achieve consistent null results, placing new upper limits on the strength of the pulsar's gravitational wave emission. A model emission mechanism is used to interpret the limits as a constraint on the pulsar's equatorial ellipticity
First upper limits from LIGO on gravitational wave bursts
We report on a search for gravitational wave bursts using data from the first
science run of the LIGO detectors. Our search focuses on bursts with durations
ranging from 4 ms to 100 ms, and with significant power in the LIGO sensitivity
band of 150 to 3000 Hz. We bound the rate for such detected bursts at less than
1.6 events per day at 90% confidence level. This result is interpreted in terms
of the detection efficiency for ad hoc waveforms (Gaussians and sine-Gaussians)
as a function of their root-sum-square strain h_{rss}; typical sensitivities
lie in the range h_{rss} ~ 10^{-19} - 10^{-17} strain/rtHz, depending on
waveform. We discuss improvements in the search method that will be applied to
future science data from LIGO and other gravitational wave detectors.Comment: 21 pages, 15 figures, accepted by Phys Rev D. Fixed a few small typos
and updated a few reference
First LIGO search for gravitational wave bursts from cosmic (super)strings
We report on a matched-filter search for gravitational wave bursts from
cosmic string cusps using LIGO data from the fourth science run (S4) which took
place in February and March 2005. No gravitational waves were detected in 14.9
days of data from times when all three LIGO detectors were operating. We
interpret the result in terms of a frequentist upper limit on the rate of
gravitational wave bursts and use the limits on the rate to constrain the
parameter space (string tension, reconnection probability, and loop sizes) of
cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR
Analysis of LIGO data for gravitational waves from binary neutron stars
We report on a search for gravitational waves from coalescing compact binary
systems in the Milky Way and the Magellanic Clouds. The analysis uses data
taken by two of the three LIGO interferometers during the first LIGO science
run and illustrates a method of setting upper limits on inspiral event rates
using interferometer data. The analysis pipeline is described with particular
attention to data selection and coincidence between the two interferometers. We
establish an observational upper limit of 1.7 \times 10^{2}M_\odot$.Comment: 17 pages, 9 figure
Search for Gravitational Wave Bursts from Soft Gamma Repeaters
We present the results of a LIGO search for short-duration gravitational
waves (GWs) associated with Soft Gamma Repeater (SGR) bursts. This is the first
search sensitive to neutron star f-modes, usually considered the most efficient
GW emitting modes. We find no evidence of GWs associated with any SGR burst in
a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190
lesser events from SGR 1806-20 and SGR 1900+14 which occurred during the first
year of LIGO's fifth science run. GW strain upper limits and model-dependent GW
emission energy upper limits are estimated for individual bursts using a
variety of simulated waveforms. The unprecedented sensitivity of the detectors
allows us to set the most stringent limits on transient GW amplitudes published
to date. We find upper limit estimates on the model-dependent isotropic GW
emission energies (at a nominal distance of 10 kpc) between 3x10^45 and 9x10^52
erg depending on waveform type, detector antenna factors and noise
characteristics at the time of the burst. These upper limits are within the
theoretically predicted range of some SGR models.Comment: 6 pages, 1 Postscript figur
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