103 research outputs found

    Changes in nasal air flow and school grades after rapid maxillary expansion in oral breathing children

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    Objective: To analyse the changes in nasal air flow and school grades after rapid maxillary expansion (RME) in oral breathing children with maxillary constriction. Material and Methods: Forty-four oral breathing children (mean age 10.57 y) underwent orthodontic RME with a Hyrax screw. Forty-four age-matched children (mean age 10.64 y) with nasal physiological breathing and adequate transverse maxillary dimensions served as the control group. The maxillary widths, nasal air flow assessed via peak nasal inspiratory flow (PNIF), and school grades were recorded at baseline, and 6 months and one year following RME. Results: After RME, there were significant increases in all the maxillary widths in the study group. PNIF was reduced in the study group (60.91 ± 13.13 l/min) compared to the control group (94.50 ± 9.89 l/min) (P < 0.000) at the beginning of the study. Six months after RME, a significant improvement of PNIF was observed in the study group (36.43 ± 22.61). School grades were lower in the study group (85.52 ± 5.74) than in the control group (89.77 ± 4.44) (P < 0.05) at the baseline, but it increased six months after RME (2.77 ± 3.90) (P < 0.001) and one year later (5.02 ± 15.23) (P < 0.05). Conclusions: Nasal air flow improved in oral breathing children six months and one year after RME. School grades also improved, but not high enough to be academically significant

    Regulation and functional role of the electron transport chain supercomplexes.

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    Mitochondria are one of the most exhaustively investigated organelles in the cell and most attention has been paid to the components of the mitochondrial electron transport chain (ETC) in the last 100 years. The ETC collects electrons from NADH or FADH2 and transfers them through a series of electron carriers within multiprotein respiratory complexes (complex I to IV) to oxygen, therefore generating an electrochemical gradient that can be used by the F1-F0-ATP synthase (also named complex V) in the mitochondrial inner membrane to synthesize ATP. The organization and function of the ETC is a continuous source of surprises. One of the latest is the discovery that the respiratory complexes can assemble to form a variety of larger structures called super-complexes (SCs). This opened an unexpected level of complexity in this well-known and fundamental biological process. This review will focus on the current evidence for the formation of different SCs and will explore how they modulate the ETC organization according to the metabolic state. Since the field is rapidly growing, we also comment on the experimental techniques used to describe these SC and hope that this overview may inspire new technologies that will help to advance the field.S

    Longitudinal evaluation of jaw muscle activity and mandibular kinematics in young patients with Class II malocclusion treated with the Teuscher activator

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    Objectives: A longitudinal study was performed to evaluate the jaw muscle activity and mandibular kinematics after Teuscher activator treatment and at 2 years after orthodontic treatment completion. Material and Methods: Twenty-seven children with Class II division 1 malocclusion were evaluated before treatment (T0; mean: 11.6 years), after functional treatment (T1; mean: 12.8 years), and 2 years after orthodontic treatment (T2; mean: 18 years). Bilateral surface electromyographic activities of the anterior temporalis, posterior temporalis, masseter, and suprahyoid muscle areas were analyzed at rest and during clenching, swallowing, and mastication. Kinematic recordings of the mandibular maximum opening, lateral shift, right and left lateral excursions, and protrusion were evaluated. Results: Compared to T0, the left masseter activity during clenching was decreased at T1 but increased at T2, similar to the other evaluated muscles. The suprahyoid activity during swallowing was increased at T1 but decreased at T2. The masseter activity during mastication was increased at T1 and further increased at T2. The left and right lateral excursions and protrusion did not show significant changes throughout the experiment. Conclusions: Teuscher activator and subsequent fixed orthodontic treatment improved jaw muscle function; however, a long period was needed to attain complete neuromuscular adaptation

    Surface electromyographic evaluation of jaw muscles in children with unilateral crossbite and lateral shift in the early mixed dentition: sexual dimorphism

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    Objectives: To examine the activity of jaw muscles at rest and during maximal voluntary clenching (MVC) in children with unilateral posterior crossbite (UPXB) and functional lateral shift in the early mixed dentition and to evaluate sex differences. Material and Methods: The sample included 30 children (15 males, 15 females) aged 6 to 10 years old, with UPXB and functional mandibular lateral shift (>=1.5 mm) in the early mixed dentition. sEMG activity coming from the muscle areas (anterior temporalis [AT], posterior temporalis [PT], masseter [MA] and suprahyoid [SH]) were obtained from both the crossbite (XB) and noncrossbite (NONXB) sides at mandibular rest position. sEMG acti- vity of the bilateral AT and MA muscles sides was obtained during MVC. Asymmetry and activity indexes were calculated for each muscle area at rest and during MVC; the MA/TA ratio during MVC was also determined. Results: At rest, no differences were found between sexes for any muscle areas or asymmetry and activity indexes. No differences were found between XB and NONXB sides. During MVC, however, significant sex differences were found in AT and MA activity, with higher sEMG values in males than in females, on both XB and NONXB sides. Asymmetry indexes, activity indexes and MA/AT ratios did not show significant differences between the sexes. Activity was symmetric both in males and in females. Conclusions: At rest, no sex differences were found, but during MVC males showed higher activity than did females in both XB and NONXB AT and MA muscle areas. Muscular activity was symmetrical at rest and during MVC in both sexes. Sexual dimorphism should be considered in the diagnosis and treatment of UPXB and lateral shift in the early mixed dentition

    Electromyographic activity of the jaw muscles and mandibular kinematics in young adults with theoretically ideal dental occlusion : reference values

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    A necessary step to use neuromuscular analysis as diagnostic tool is to establish normal reference values for the physiological range in a healthy population. Surface electromyographic (sEMG) activity of the jaw muscles and mandibular kinematics were measured in young adults with theoretically ideal dental occlusion to determine normal reference values during different tasks. Differences between the sexes were evaluated. Forty young adults (20 men, 20 women; mean age 22.8 ± 3.9 years) with theoretically ideal dental occlusion were selected using very restrictive criteria. sEMG activity of the anterior temporalis (AT), posterior temporalis, masseter (MA), and suprahyoid muscles were evaluated in the rest position and during swallowing, mastication, and clenching. Mandibular kinematics in the rest position and during maximum excursions were assessed. Asymmetry, activity, and torque indices and MA/AT ratios were calculated. For all muscles, sEMG values were 1.01-3.57 µV at rest, 3.50-10.85 µV during swallowing, and 41.04-86.59 µV during mastication. During clenching, values were 230.08-243.55 µV for the AT and MA muscles. Mean total asymmetry, activity, and torque indices at rest were 20.34 %, -15.04 %, and 19.02 %, respectively; during clenching, these values were 6.14 %, -2.62 %, and 4.46 %. MA/AT ratios were near 1. Kinematic measurements during lateral excursion, protrusive and maximum opening were 7.54, 8.44, and 37.38 mm respectively; lateral mandibular shift was 1.41 mm; free way and lateral displacement at rest were 1.40 and 0.26 mm. Right MA activity during mastication and clenching was higher in men than women. Reference values for sEMG activity and mandibular kinematics were determined. Some muscular asymmetry and torque were observed

    Longitudinal evaluation of sEMG of masticatory muscles and kinematics of mandible changes in children treated for unilateral cross-bite

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    a b s t r a c t The aim of this study was to evaluate masticatory muscle activity and kinematics of mandible changes in children with unilateral posterior cross-bite (UPXB) after orthodontic treatment, and one year after retention. Twenty-five children with UPXB and functional mandibular shift were evaluated before treatment (mean age 12.5 years), after treatment (mean age 14.9 years), and one year after retention (mean age 16.8 years). The same data were collected in a control group of thirty age-matched normocclusive children. Simultaneous bilateral surface electromyographic (sEMG) activity from anterior temporalis (AT), posterior temporalis (PT), masseter (MA), and supra-hyoid (SH) muscle areas were evaluated at rest, during swallowing, mastication and clenching. Kinematic records of rest position, mandibular lateral shift, swallowing and mastication were analyzed. Results showed a lateral shift of the mandible present at rest. During swallowing, sEMG activity of SH predominated before and post-treatment and retention. High frequency of immature swallowing was maintained post-treatment and retention. During mastication, MA activity increased significantly and its asymmetry was corrected post-treatment. During clenching, cross-bite side AT and MA activity increased significantly posttreatment and remained stable after retention, and MA/AT ratio reversed. These findings reinforce the advantages of treating children with UPXB and functional shift as early as possible

    The northeastern sector of the Guadalquivir Foreland Basin (Betic Cordillera, Late Miocene): stratigraphy, chronology and sedimentary evolution

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    Estudios estratigráficos y sedimentológicos de afloramiento y el análisis paleoecológico y bioestratigráfico mediante foraminíferos, han permitido realizar una reinterpretación sedimentaria de las unidades de margas y areniscas miocenas del sector nororiental de la Cuenca del Guadalquivir. El relleno sedimentario ha sido dividido en cuatro unidades litoestratigráficas (I-IV), todas ellas depositadas durante el Tortoniense, entre 10 y 7.89 Ma, aproximadamente. La Unidad I (Tortoniense antiguo no basal) está fomada por arenas y calizas de algas, y es interpretada como una unidad transgresiva y expansiva sobre el basamento que evoluciona desde ambientes marinos someros a rampa de carbonatos tipo rhodalgal. La Unidad II (Tortoniense inferior, biozona MMi11: entre 10 y 9.54 Ma) está caracterizada por una alternancia rítmica de margas arcillosas y silíceas, depositadas en ambientes pelágicos y profundos de aguas frías-eutróficas, si bien con repetidos cambios en la estratificación y distribución de nutrientes en la columna de agua. Esta unidad registra una importante somerización en su parte superior, dando paso gradual a la Unidad III. La Unidad III (Tortoniense inferior, biozonaMMi11: desde 9.54 Ma) está dominada por areniscas, aunque lateralmente aparecen brechas intraformacionales con estratos contorsionados. Está nutrida por deltas desde la costa y se interpreta como el depósito de bancos arenosos movilizados por la acción de corrientes mareales y el oleaje de tormentas en rampas. La Unidad IV (Tortoniense superior, biozona MMi12: desde 8.35 Ma) está representada por margas pelágicas similares a las de la Unidad II, de la que difiere por la presencia de intercalaciones arenosas genéticamente relacionadas con procesos mareales y de tormentas.A sedimentary revision of the marls and sandstone Miocene Units from the northeastern part of the Guadalquivir basin is here reported. Stratigraphical and sedimentological studies from field outcrop and biostratigraphical and palaeoecological analysis from field samples support the interpretations and results. The sedimentary infilling of the studied part of the basin is divided into four lihostratigraphic units (I to IV). Unit I (Lowermost Tortonian) is mainly represented by calcareous sandstone interpreted as the deposition at coastal systems vertically evolving to rhodalgal ramp environment. Unit II (Lower Tortonian, biozone MMi11: ca. 10-9.54 Ma) is formed by a rhythmite of silty and siliceous marls deposited in pelagic conditions of cold-eutrophic water. Foraminifera record a basinal shallowing from deep water. Heterolithic Unit III (Lower Tortonian, biozoneMMi11: since 9.54Ma) mainly consist of sandstones but slumped brecchias and marls laterally also occur. It is interpreted as sand banks or sand crestal ridges fed from northern margin deltas and controlled by tidal and storm currents in a starved pelagic ramp. Unit IV (Upper Tortonian, biozone MMi12: since 8.35 Ma) is mainly marly and the sedimentary interpretation is analogue to that of Unit III but in a deeper ramp.El estudio se ha financiado por el Proyecto de Investigación CGL2009-07830/BTE (Ministerio de Educación y Ciencia, y Fondos Europeos de Desarrollo Regional-FEDER) y por el Grupo de Investigación RNM-200 (F.G.) de la Junta de Andalucía

    Association between Crystalline Silica Dust Exposure and Silicosis Development in Artificial Stone Workers

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    Occupational exposure to respirable crystalline silica (SiO2 ) is one of the most common and serious risks because of the health consequences for the workers involved. Silicosis is a progressive, irreversible, and incurable fibrotic lung disease caused by the inhalation of respirable crystalline silica dust. A cross-sectional epidemiological study was carried out to assess the occupational risk factors that may contribute to the onset of silicosis in workers carrying out work activities with the inhalation of silica compact dust. The study population consisted of 311 artificial stone workers from the province of Almeria (southeast of Spain). Among them, 64 were previously diagnosed with silicosis and the rest of the participants (n = 247 workers) were not diagnosed with such a disease. The workers showing a greater risk of developing silicosis were those who installed kitchen worktops at consumers’ homes, as they did not use face-masks or were not provided with personal protective equipment (PPE) by their business. The results of this study provide support for the evidence indicating that silicosis is a major emerging health concern for workers in the artificial stone sector. Exposure to crystalline silica dust thus can influence the development of silicosis in those cases where individual and collective protection measures are not used or adequately applied

    Cloud Detection and Tracking Based on Object Detection with Convolutional Neural Networks

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    Due to the need to know the availability of solar resources for the solar renewable technologies in advance, this paper presents a new methodology based on computer vision and the object detection technique that uses convolutional neural networks (EfficientDet-D2 model) to detect clouds in image series. This methodology also calculates the speed and direction of cloud motion, which allows the prediction of transients in the available solar radiation due to clouds. The convolutional neural network model retraining and validation process finished successfully, which gave accurate cloud detection results in the test. Also, during the test, the estimation of the remaining time for a transient due to a cloud was accurate, mainly due to the precise cloud detection and the accuracy of the remaining time algorithm
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