329 research outputs found

    Rapid assessment of nonlinear optical propagation effects in dielectrics

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    8 págs.; 6 figs.; Open Access funded by Creative Commons Atribution Licence 4.0Ultrafast laser processing applications need fast approaches to assess the nonlinear propagation of the laser beam in order to predict the optimal range of processing parameters in a wide variety of cases. We develop here a method based on the simple monitoring of the nonlinear beam shaping against numerical prediction. The numerical code solves the nonlinear Schrodinger equation with nonlinear absorption under simplified conditions by employing a state-of-the art computationally efficient approach. By comparing with experimental results we can rapidly estimate the nonlinear refractive index and nonlinear absorption coefficients of the material. The validity of this approach has been tested in a variety of experiments where nonlinearities play a key role, like spatial soliton shaping or fs-laser waveguide writing. The approach provides excellent results for propagated power densities for which free carrier generation effects can be neglected. Above such a threshold, the peculiarities of the nonlinear propagation of elliptical beams enable acquiring an instantaneous picture of the deposition of energy inside the material realistic enough to estimate the effective nonlinear refractive index and nonlinear absorption coefficients that can be used for predicting the spatial distribution of energy deposition inside the material and controlling the beam in the writing process.This work has been partly funded by MINECO TEC2011-22422 project. J. de H. acknowledges funding from the JAE CSIC Program (pre-doctoral fellowship co-funded by the European Social Fund). A.P. acknowledges support from the People Program (Marie Curie Actions) Incoming International Fellowship (CHRONOS) under REA grant agreement nu [327627].Peer Reviewe

    Role of fluorine-18 fluorodeoxyglucose PET/CT in head and neck oncology: the point of view of the radiation oncologist

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    Squamous cell carcinoma is the most common malignant tumour of the head and neck. The initial TNM staging, the evaluation of the tumour response during treatment, and the long-term surveillance are crucial moments in the approach to head and neck squamous cell carcinoma (HNSCC). Thus, at each of these moments, the choice of the best diagnostic tool providing the more precise and larger information is crucial. Positron emission tomography with fluorine-18 fludeoxyglucose integrated with CT (F-18-FDG-PET/CT) rapidly gained clinical acceptance, and it has become an important imaging tool in routine clinical oncology. However, controversial data are currently available, for example, on the role of F-18-FDG-PET/CT imaging during radiotherapy planning, the prognostic value or its real clinical impact on treatment decisions. In this article, the role of F-18-FDG-PET/CT imaging in HNSCC during pre-treatment staging, radiotherapy planning, treatment response assessment, prognosis and follow-up is reviewed focusing on current evidence and controversial issues. A proposal on how to integrate F-18-FDG-PET/CT in daily clinical practice is also described

    Effects of Sex, Age and Height on Symphysis–Ischial Spine Distance Measured on a Pelvic CT

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    Objective: To examine the influence of age, sex and height on the symphysis–ischial spine distance (SID) measured on pelvic Computed tomography (CT)images in subjects of reproductive age, and to determine the interobserver reproducibility. This measurement (SID) is of great importance because the use of intrapartum ultrasound is based on the assumption of a specific value (30 mm) of such a measurement. Methods: This was a cross-sectional descriptive study in which SID was measured in subjects aged 20 to 44 years who had been scheduled for pelvic CT at our centre from January 2018 to May 2021 for different reasons. Radiographic measurements of the pelvis were obtained through the multiplanar reconstruction of the CT image. The images obtained from all of the participants were independently assessed by three senior radiologists, and the SID measurements made by each one were blinded from those of the remaining observers. Correlations between the SID and patient age, height and sex were analyzed by univariate and multivariate linear regression. Results: The mean SID for 87 of the enrolled participants (45 women, 42 men) was 28.2 ± 6.25 mm. Among the observers, the mean difference in this distance was 1 to 2 mm, and was scarcely related to measurement size, with agreement being greater than 70%. The mean SID was significantly related to sex and height (SID = −24.9 − 6.51 × sex (0 or 1) + 0.34 × height (cm); p = 0.01; sex equals 1 for a man and 0 for a woman), such that it was a mean of 2.5 mm greater in women than men (29.50 mm vs. 26.99 mm). Conclusion: Measurements of SID on CT images show good interobserver reproducibility, and are related to sex and height.Depto. de Salud Pública y Materno - InfantilFac. de MedicinaTRUEUnión EuropeaComunidad de MadridInstituto de Salud Carlos IIIHalekulani S.L.pu

    Effects of gluteal kinesio-taping on performance with respect to fatigue in rugby players

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    Kinesio-tape® has been suggested to increase blood circulation and lymph flow and might influence the muscle's ability to maintain strength during fatigue. Therefore, the aim of this study was to investigate the influence of gluteal Kinesio-tape® on lower limb muscle strength in non-fatigued and fatigued conditions. A total of 10 male rugby union players performed 20-m sprint and vertical jump tests before and after a rugby-specific fatigue protocol. The 20-m sprint time was collected using light gates (SMARTSPEED). A 9-camera motion analysis system (VICON, 100 Hz) and a force plate (Kistler, 1000 Hz) measured the kinematics and kinetics during a counter movement jump and drop-jump. The effect of tape and fatigue on jump height, maximal vertical ground reaction force, reactivity strength index as well as lower limb joint work were analysed via a two-way analysis of variance. The fatigue protocol resulted in significantly decreased performance of sprint time, jump heights and alterations in joint work. No statistical differences were found between the taped and un-taped conditions in non-fatigued and fatigued situation as well as in the interaction with fatigue. Therefore, taping the gluteal muscle does not influence the leg explosive strength after fatiguing in healthy rugby players

    Current guidelines for the implementation of flywheel resistance training technology in sports:a consensus statement

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    BackgroundFlywheel resistance training has become more integrated within resistance training programs in a variety of sports due to the neuromuscular, strength, and task-specific enhancements reported with this training.ObjectiveThis paper aimed to present the consensus reached by internationally recognized experts during a meeting on current definitions and guidelines for the implementation of flywheel resistance training technology in sports.MethodsNineteen experts from different countries took part in the consensus process; 16 of them were present at the consensus meeting (18 May 2023) while three submitted their recommendations by e-mail. Prior to the meeting, evidence summaries were developed relating to areas of priority. This paper discusses the available evidence and consensus process from which recommendations were made regarding the appropriate use of flywheel resistance training technology in sports. The process to gain consensus had five steps: (1) performing a systematic review of systematic reviews, (2) updating the most recent umbrella review published on this topic, (3) first round discussion among a sample of the research group included in this consensus statement, (4) selection of research group members—process of the consensus meeting and formulation of the recommendations, and (5) the consensus process. The systematic analysis of the literature was performed to select the most up-to-date review papers available on the topic, which resulted in nine articles; their methodological quality was assessed according to AMSTAR 2 (Assessing the Methodological Quality of Systematic Review 2) and GRADE (Grading Recommendations Assessment Development and Evaluation). Statements and recommendations scoring 7–9 were considered appropriate.ResultsThe recommendations were based on the evidence summary and researchers’ expertise; the consensus statement included three statements and seven recommendations for the use of flywheel resistance training technology. These statements and recommendations were anonymously voted on and qualitatively analyzed. The three statements reported a score ranging from 8.1 to 8.8, and therefore, all statements included in this consensus were considered appropriate. The recommendations (1–7) had a score ranging from 7.7 to 8.6, and therefore, all recommendations were considered appropriate.ConclusionsBecause of the consensus achieved among the experts in this project, it is suggested that practitioners and researchers should adopt the guidelines reported in this consensus statement regarding the use of flywheel resistance technology in sports

    Building the Future Therapies for Down Syndrome: The Third International Conference of the T21 Research Society

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    Research focused on Down syndrome has increased in the last several years to advance understanding of the consequences of trisomy 21 (T21) on molecular and cellular processes and, ultimately, on individuals with Down syndrome. The Trisomy 21 Research Society (T21RS) is the premier scientific organization for researchers and clinicians studying Down syndrome. The Third International Conference of T21RS, held June 6–9, 2019, in Barcelona, Spain, brought together 429 scientists, families, and industry representatives to share the latest discoveries on underlying cellular and molecular mechanisms of T21, define cognitive and behavioral challenges and better understand comorbidities associated with Down syndrome, including Alzheimer’s disease and leukemia. Presentation of cutting-edge results in neuroscience, neurology, model systems, psychology, cancer, biomarkers and molecular and phar­ma­cological therapeutic approaches demonstrate the compelling interest and continuing advancement in all aspects of understanding and ameliorating conditions associated with T21

    Incidencia del ejercicio físico y el entrenamiento vibratorio sobre la amplitud de movimiento de mujeres con fibromialgia

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    Objetivo. En la presente investigación hemos planteado como objetivos principales, por un lado, valorar el efecto del ejercicio físico y el entrenamiento vibratorio sobre la amplitud de movimiento en mujeres con fibromialgia (FM) y, por otro, determinar si existe alguna relación entre dicha variable y el dolor y la rigidez. Método. La muestra estuvo constituida por un total de cuarenta y seis mujeres (edad: 58,2 ± 8,5 años; peso: 72,1 ± 9,6 kg; altura: 156,9 ± 6,1 cm) diagnosticadas con FM. Los participantes fueron divididos aleatoriamente en tres grupos: ejercicio físico y entrenamiento vibratorio (WBV + EJ; n = 15); ejercicio físico sin vibraciones (EJ; n = 15) y un grupo control (GC; n = 16). Los grupos WBV + EJ y EJ realizaron dos sesiones semanales de ejercicio físico durante 8 semanas. Además, los integrantes de WBV + EJ realizaron 3 sesiones semanales de entrenamiento vibratorio (30 Hz, 4 mm). Las pruebas de evaluación incluyeron el test de sit and reach (variable principal), la valoración del número de tender points (TP) y una escala analógica visual (VAS) para determinar la rigidez. Resultados. Los resultados derivados del análisis intra e intergrupo no mostraron diferencias significativas en la rigidez o el número de TP, si bien, la prueba de sit and reach mostró una mejora estadísticamente significativa en WBV + EJ (58%; p < 0,05). El análisis correlacional mostró una relación inversa (r = -0,55; p < 0,05) entre el sit and reach y el número de TP. Conclusión. Como conclusión, podemos indicar que los datos obtenidos en la presente investigación han mostrado los efectos significativos del entrenamiento vibratorio sobre la amplitud de movimiento en mujeres con FM, aunque el número de TP o la rigidez no se vieron afectados en ningún caso
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