412 research outputs found

    Jaw biodynamic data for 24 patients with chronic unilateral temporomandibular disorder

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    This study assessed 24 adult patients, suffering from severe chronic unilateral pain diagnosed as temporomandibular joint (TMJ) disorder (TMD). The full dentate patients had normal occlusion and had never received an occlusal therapy, i.e., were with natural dental evolution/maturation. The following functional and dynamic factors were assessed: (1) chewing function; (2) TMJ remodeling or the condylar path (CP); and (3) lateral jaw motion or lateral guidance (LG). CPs were assessed using conventional axiography, and LG was assessed by K7 jaw tracking. Seventeen (71%) of the 24 (100%) patients consistently showed a habitual chewing side. The mean (standard deviation [SD]) of the CP angles was 47.90 (9.24) degrees. The mean (SD) of the LG angles was 42.95 (11.78) degrees. Data collection emerged from the conception of a new TMD paradigm where the affected side could be the habitual chewing side, the side with flatter lateral jaw motion or the side with an increased CP angle. These data may lead to improved diagnosis, therapy plans and evolution in TMD patients

    Anthropometric Specificity and Level of Participation in Acrobatic Gymnastics Based on Sex

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    AGRADECIMIENTOS. A todos los gimnastas de acrobática y entrenadores de los clubs de Gimnasia en España.Las diferencias de sexo es un aspecto muy presente en el mundo laboral y deportivo. Esto se traduce en la diferenciación de actividades deportivas, determinadas como masculinas o femeninas. De ahí que el objetivo del estudio fue analizar el nivel de participación y características morfológicas en gimnastas de acrobática y ver las diferencias en relación al sexo y rol: portor y ágil. Se analizó la participación en los Campeonatos de España entre 2011 y 2018, y se comparó medidas antropométricas, composición corporal y de proporcionalidad, en función del rol de actuación y sexo. El Comité Autonómico de Ética de Investigación de la Xunta de Galicia (España) aprobó la metodología de trabajo. Los resultados mostraron un porcentaje mucho mayor de participación en función del sexo a favor del sexo femenino en todos los campeonatos analizados. Sin embargo, el peso, índice de masa corporal y el porcentaje muscular no fueron diferentes entre sexos en ninguno de los dos roles. De las 62 variables morfológicas evaluadas, existe un mayor predominio de las diferencias en los portores que en los ágiles en relación al sexo, destacando el porcentaje de grasa.Sex differences are a very present aspect in the world of work and sports. This translates into the differentiation of sports activities, determined as masculine or feminine. Hence, the aim of the study was to analyze the level of participation and morphological characteristics in acrobatic gymnasts and to see the differences in relation to sex and role: Base and top. Participation in the Spanish Championships between 2011 and 2018 was analyzed, and anthropometric measures, body composition and proportionality were compared, depending on the role of performance and sex. The Autonomous Committee of Research Ethics of the Xunta de Galicia (Spain) approved the work methodology. The results showed a much higher percentage of participation according to sex in favor of the female sex in all the analyzed championships. However, the weight, body mass index and muscle percentage were not different between sexes in either of the two roles. Of the 62 morphological variables evaluated, there is a greater predominance of differences in the bases than in the tops ones in relation to sex, highlighting the percentage of fat

    Efficient dual-wavelength excitation of Tb3+ emission in rare-earth doped KYF4 cubic nanocrystals dispersed in silica sol-gel matrix

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    Energy transfer from Ce3+ to Tb3+ ions under UV excitation, giving rise to visible emissions, is investigated in sol–gel derived transparent nano-glass–ceramics containing cubic KYF4 nanocrystals, for different doping concentrations of rare-earth ions. Moreover, visible emissions of Tb3+ are also obtained under near-infrared excitation through energy transfer from Yb3+ ions by means of cooperative up-conversion processes. Thus, Ce3+–Tb3+–Yb3+ doped nano-glass–ceramics can be activated in a dual-wavelength mode yielding efficient blue–green emissions of particular interest in photovoltaic silicon solar cells and white-light emitting diodes

    Life history of an anticyclonic eddy

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    19 pages, 11 figures, 1 table, supporting information https://doi.org/10.1029/2004JC002526We use the trajectory of three buoys dragged below the surface mixed layer, together with sea surface temperature imagery, to examine the evolution of an anticyclonic warm-core eddy since its generation by the Canary Islands. Two buoys remain within the eddy during some 100 days, and the third one remains almost 200 days, while drifting southwestward up to 500 km with the mean Canary Current. The eddy merges with several younger anticyclonic and cyclonic eddies, in each occasion, suffering substantial changes. The eddy core, defined as a region with near-solid-body-type rotation and radial convergence, initially occupies the whole eddy. After interacting with another vortex the inner core markedly slows down, although it continues displaying radial convergence and relatively small radial oscillations, and an uncoupled outer ring is formed or enhanced, which revolves even more slowly and displays large radial fluctuations. The vortex extensive life is consistent with its inertially stable character and observations of radial convergence. A very simple model of vortex merging, where cylinders fuse conserving mass and angular momentum, gives fair results. The observations suggest that the eddy changes, as the result of its own slow evolution and sporadic mixing events, from a young stage, where the core retains its vorticity and occupies most of the eddy, through a mature stage, where the eddy has a reduced inner core and a slowly revolving outer ring, to a decay stage, where the vorticity maximum is substantially reducedThis work has been supported by the Spanish government through projects FRENTES (AMB95-0731), COCA (REN2000-1471-C02-02MAR), and BREDDIES (REN2001-2650/ANT) and the special action MAR1999-1489-E and by the European Union through projects CANIGO (MAS3-CT96-0060) and OASIS (EVK3-CT-2002-00073-OASIS)Peer Reviewe

    The Noncommutative Harmonic Oscillator based in Simplectic Representation of Galilei Group

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    In this work we study symplectic unitary representations for the Galilei group. As a consequence the Schr\"odinger equation is derived in phase space. The formalism is based on the non-commutative structure of the star-product, and using the group theory approach as a guide a physical consistent theory in phase space is constructed. The state is described by a quasi-probability amplitude that is in association with the Wigner function. The 3D harmonic oscillator and the noncommutative oscillator are studied in phase space as an application, and the Wigner function associated to both cases are determined.Comment: 7 pages,no figure

    Angiogenic response in an in vitro model of dog microvascular endothelial cells stimulated with antigenic extracts from Dirofilaria immitis adult worms

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    Background Angiogenesis can occur under pathological conditions when stimuli such as inflammation, vascular obstruction or hypoxia exist. These stimuli are present in cardiopulmonary dirofilariosis (Dirofilaria immitis). The aim of this study was to analyze the capacity of D. immitis antigens to modify the expression of angiogenic factors and trigger the formation of pseudocapillaries (tube-like structures) in an in vitro model of endothelial cells. Methods The expression of VEGF-A, sFlt, mEndoglin and sEndoglin in cultures of canine microvascular endothelial cells stimulated with extract of adult worms of D. immitis obtained from an untreated dog (DiSA) and from a dog treated for 15 days with doxycycline (tDiSA), was determined by using commercial kits. The capacity of pseudocapillary formation was evaluated analyzing cell connections and cell groups in Matrigel cell cultures stimulated with DiSA and tDiSA. In both cases non-stimulated cultures were used as controls. Results First, we demonstrated that worms obtained from the dog treated with doxycycline showed a significantly lower amount of Wolbachia (less than 60%) than worms removed from the untreated dog. Only DiSA was able to significantly increase the expression of the proangiogenic factor VEGF-A in the endotelial cells cultures. None of the D. immitis extracts modified the expression of sFlt. tDiSA extract was able to modify the expression of the endoglins, significantly decreasing the expression of the pro-angiogenic mEndoglin and increasing the anti-angiogenic sEndoglin. The formation of pseudocapillaries was negatively influenced by tDiSA, which reduced the organization and number of cellular connections. Conclusions The ability of antigens from adult D. immitis worms to modify the expression of pro and anti-angiogenic factors in endotelial cell cultures was demonstrated, as well as the trend to form pseudocapillaries in vitro. The capacity of stimulation may be linked to the amount of Wolbachia present in the antigenic extracts

    Biochemical and structural characterization of a novel arginine kinase from the spider <i>Polybetes pythagoricus</i>

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    Energy buffering systems are key for homeostasis during variations in energy supply. Spiders are the most important predators for insects and therefore key in terrestrial ecosystems. From biomedical interest, spiders are important for their venoms and as a source of potent allergens, such as arginine kinase (AK, EC 2.7.3.3). AK is an enzyme crucial for energy metabolism, keeping the pool of phosphagens in invertebrates, and also an allergen for humans. In this work, we studied AK from the Argentininan spider Polybetes pythagoricus (PpAK), from its complementary DNA to the crystal structure. The PpAK cDNA from muscle was cloned, and it is comprised of 1068 nucleotides that encode a 384-amino acids protein, similar to other invertebrate AKs. The apparent Michaelis-Menten kinetic constant (Km) was 1.7 mM with a kcat of 75 s-1. Two crystal structures are presented, the apoPvAK and PpAK bound to arginine, both in the open conformation with the active site lid (residues 310-320) completely disordered. The guanidino group binding site in the apo structure appears to be organized to accept the arginine substrate. Finally, these results contribute to knowledge of mechanistic details of the function of arginine kinase.Instituto de Investigaciones Bioquímicas de La Plat

    Perceived stress in dentists and dental students of Latin America and the Caribbean during the mandatory social isolation measures for the covid-19 pandemic : a cross-sectional study

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    This study aims to determine the impact of the COVID-19 pandemic, specifically considering the mandatory social isolation measures implemented, on the perceived stress of a sample of dentists and dental students from Latin America and the Caribbean, as well as the associated sociodemographic and pandemic-related variables. A cross-sectional survey was conducted with a sample of 2036 dentists and dental students (1433 women). For the main outcome, the 14-item Perceived Stress Scale (PSS-14) was used. The survey also questioned sociodemographic aspects, questions on the COVID-19 pandemic, health variables, and habits. Descriptive, bivariate, and multivariate analyses (linear regression) were applied to observe the factors associated with perceived stress. The PSS-14 mean score was 24.76 (±11.76). Hierarchical regression models showed significant variables associated with the PSS-14 scores: income level during mandatory social isolation, having older adults under care during mandatory social isolation, self-perceived level of concern regarding COVID-19, self-perceived health, Coffee consumption during mandatory social isolation. In general terms, the pandemic has influenced the personal, social, labor, and everyday life of dental staff and affected the mental health of this population specifically when perceived stress is considered. Public policies, strategies, and mental health surveillance systems are required for this population

    Biochemical and structural characterization of a novel arginine kinase from the spider <i>Polybetes pythagoricus</i>

    Get PDF
    Energy buffering systems are key for homeostasis during variations in energy supply. Spiders are the most important predators for insects and therefore key in terrestrial ecosystems. From biomedical interest, spiders are important for their venoms and as a source of potent allergens, such as arginine kinase (AK, EC 2.7.3.3). AK is an enzyme crucial for energy metabolism, keeping the pool of phosphagens in invertebrates, and also an allergen for humans. In this work, we studied AK from the Argentininan spider Polybetes pythagoricus (PpAK), from its complementary DNA to the crystal structure. The PpAK cDNA from muscle was cloned, and it is comprised of 1068 nucleotides that encode a 384-amino acids protein, similar to other invertebrate AKs. The apparent Michaelis-Menten kinetic constant (Km) was 1.7 mM with a kcat of 75 s-1. Two crystal structures are presented, the apoPvAK and PpAK bound to arginine, both in the open conformation with the active site lid (residues 310-320) completely disordered. The guanidino group binding site in the apo structure appears to be organized to accept the arginine substrate. Finally, these results contribute to knowledge of mechanistic details of the function of arginine kinase.Instituto de Investigaciones Bioquímicas de La Plat
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