10 research outputs found
Can kinematic and kinetic differences between planned and unplanned volleyball block jump-landings be associated with injury risk factors?
Introduction: Injury prevention programs for athletes are still limited by a lack of understanding of specific risk factors that can influence injuries within different sports. The majority of studies on volleyball have not considered the movement patterns when moving in different directions or in planned and unplanned block jump-landings.
Methods: This study investigated all planes mechanics between the lead and trail limb when moving in dominant and non-dominant directions, for both planned and unplanned jump-landings in thirteen semi-professional female volleyball players. Ankle, knee and hip joint kinematics, kinetics and joint stiffness were recorded.
Results: Our results showed statistically significant differences between the lead limb and the trail limb in the hip flexion angles, moments and velocity; in the knee flexion angles, moments, stiffness, power and energy absorption and in the ankle dorsiflexion, power and energy absorption, showing a tendency where the lead limb has a higher injury risk than the trail limb. When considering planned versus unplanned situations, there were statistically significant differences in knee flexion angles, moments, power and energy absorption; and hip contact angle,
flexion angular velocity and energy absorption, with musculoskeletal adaptations in the planned situations.
Discussion: It appears that the role of the limb, either lead or trail, is more important than the limb dominance when performing directional jump-landings, with the lead limb having a higher implication on possible overuse injuries than the trail limb. Furthermore, planned movements showed a difference in strategy indicating greater implications to possible overuse injuries than in the unplanned situations which may be associated with more conscious thought about the movements.
Conclusion: Coaches should consider unilateral coordination training in both landing directions for the lead and trail limb, and should adapt training to replicate the competition environment, using unplanned situations to minimize asymmetries to might reduce injury risks
Hardening study of 28nm FDSOI technology at very high doses of ionizing radiation
Ionizing radiation causes malfunction in electronic systems, from miscalculations to a total device failure. At nanometric scale, high-energy radiation produces charges liable to be trapped in the insulating oxides of the device. These trapped charges will produce electrical degradation that manifest in MOSFET devices as a negative threshold voltage shift, a subthreshold slope weakening, and an increase in leakage currents. The resilience of electronic systems to these degradation is essential in radioactive environments such as space, nuclear power plants or in the least desired case, nuclear accidents.This work seeks to explore two research approaches with the aim of studying their impact on the recovery of the electrical characteristics of 28 nm FDSOI devices after their exposure to ionizing radiation. This thesis proposes a new regeneration-compensation hardening method based on the detrapping of charges by applying thermal annealing cycles on the one hand and on the other hand the electrical compensation of the threshold voltage allowed by the inherent possibility of the 28nm FDSOI technology to apply a back-gate bias. This method could be validated through physical modeling of radiation effects and recovery mechanisms, as well as experiments with FDSOI devices. Furthermore, simulations carried out with basic FDSOI cells typically used in digital circuits enabled the prediction of their degradation and recovery, thus further validating the proposed recovery method.Les rayonnements ionisants provoquent des dysfonctionnements dans les systèmes électroniques, de la simple erreur de calcul au dysfonctionnement total de l’appareil. À l'échelle nanométrique, les rayonnements ionisants d’énergie élevée produisent des charges susceptibles d'être piégées dans les oxydes isolants du dispositif. Ces charges piégées produisent des dégradations électriques qui se manifestent dans les dispositifs MOSFET par un décalage négatif de la tension de seuil, un affaiblissement de la pente sous-seuil et une augmentation des courants de fuite. La résilience des systèmes électroniques à ces dégradations est essentielle dans les environnements radiatifs tels que l'espace, les centrales nucléaires ou dans le cas le moins souhaité des accidents nucléaires.Ce travail vise à explorer deux axes de recherche dans le but d'étudier leur impact sur la récupération des caractéristiques électriques de dispositifs 28nm FDSOI ayant été exposés à des rayonnements ionisants. Cette thèse propose une nouvelle méthode de durcissement par régénération-compensation basée sur le dépiégeage des charges par application de cycles de recuit thermique d’une part et d’autre part sur la compensation électrique de la tension de seuil autorisée par la capacité inhérente à la technologie 28nm FDSOI d'appliquer une polarisation back-gate. Cette méthode a pu être validée par la modélisation physique des effets des rayonnements et des mécanismes de récupération, ainsi que par des expériences avec des dispositifs FDSOI. De plus, des simulations réalisées avec des cellules FDSOI basiques typiquement utilisées dans les circuits numériques ont permis de prédire leur dégradation et leur récupération, validant ainsi davantage la méthode de récupération proposée
Etude de durcissement de la technologie 28 nm FDSOI aux très fortes doses de radiation ionisante
Les rayonnements ionisants provoquent des dysfonctionnements dans les systèmes électroniques, de la simple erreur de calcul au dysfonctionnement total de l’appareil. À l'échelle nanométrique, les rayonnements ionisants d’énergie élevée produisent des charges susceptibles d'être piégées dans les oxydes isolants du dispositif. Ces charges piégées produisent des dégradations électriques qui se manifestent dans les dispositifs MOSFET par un décalage négatif de la tension de seuil, un affaiblissement de la pente sous-seuil et une augmentation des courants de fuite. La résilience des systèmes électroniques à ces dégradations est essentielle dans les environnements radiatifs tels que l'espace, les centrales nucléaires ou dans le cas le moins souhaité des accidents nucléaires.Ce travail vise à explorer deux axes de recherche dans le but d'étudier leur impact sur la récupération des caractéristiques électriques de dispositifs 28nm FDSOI ayant été exposés à des rayonnements ionisants. Cette thèse propose une nouvelle méthode de durcissement par régénération-compensation basée sur le dépiégeage des charges par application de cycles de recuit thermique d’une part et d’autre part sur la compensation électrique de la tension de seuil autorisée par la capacité inhérente à la technologie 28nm FDSOI d'appliquer une polarisation back-gate. Cette méthode a pu être validée par la modélisation physique des effets des rayonnements et des mécanismes de récupération, ainsi que par des expériences avec des dispositifs FDSOI. De plus, des simulations réalisées avec des cellules FDSOI basiques typiquement utilisées dans les circuits numériques ont permis de prédire leur dégradation et leur récupération, validant ainsi davantage la méthode de récupération proposée.Ionizing radiation causes malfunction in electronic systems, from miscalculations to a total device failure. At nanometric scale, high-energy radiation produces charges liable to be trapped in the insulating oxides of the device. These trapped charges will produce electrical degradation that manifest in MOSFET devices as a negative threshold voltage shift, a subthreshold slope weakening, and an increase in leakage currents. The resilience of electronic systems to these degradation is essential in radioactive environments such as space, nuclear power plants or in the least desired case, nuclear accidents.This work seeks to explore two research approaches with the aim of studying their impact on the recovery of the electrical characteristics of 28 nm FDSOI devices after their exposure to ionizing radiation. This thesis proposes a new regeneration-compensation hardening method based on the detrapping of charges by applying thermal annealing cycles on the one hand and on the other hand the electrical compensation of the threshold voltage allowed by the inherent possibility of the 28nm FDSOI technology to apply a back-gate bias. This method could be validated through physical modeling of radiation effects and recovery mechanisms, as well as experiments with FDSOI devices. Furthermore, simulations carried out with basic FDSOI cells typically used in digital circuits enabled the prediction of their degradation and recovery, thus further validating the proposed recovery method
Factores de riesgo asociados a complicaciones en cirugía de reconstrucción de pared abdominal: revisión sistematizada de la literatura
Introducción: Los costos generados por la corrección de las eventraciones abdominales no solo se deben a técnicas quirúrgicas más complejas y el uso de materiales protésicos costosos. La evolución de estas técnicas quirúrgicas ha permitido tener procedimientos con reconstrucciones más fisiológicas, pero con una mayor tasa de complicaciones.
Objetivo: Evaluar la literatura sobre los factores de riesgo con mayor fuerza de asociación para complicaciones de cirugía de reconstrucción de pared abdominal. Métodos: Se realizó una revisión sistematizada en la literatura buscando estudios realizados en pacientes con factores de riesgo para complicaciones de cirugía de reconstrucción de pared abdominal. Resultados: El rango de complicaciones es muy amplio, hay series que muestran tasas tan bajas como 1,94% y otras que llegan hasta el 36%. Las complicaciones infecciosas del sitio operatorio son las más frecuentes llegando a alcanzar hasta un 57% del global de las complicaciones. En orden descendente las siguientes son: Complicaciones gastrointesinales (19%), dolor (17%) Hematologicas (8%), cardiacas (8%), pulmonares (6%), hepatobiliares (2%). Los factores de riesgo más frecuentes corresponden a: diabetes mellitus, tabaquismo, obesidad, cirugía concomitante y sarcopenia. Conclusiones: Existen algunos factores de riesgo descritos en la literatura que podrían aumentar la tasa de complicaciones en esta cirugía. Se deben realizar estudios tratando de controlar estas variables para poder optimizar la prehabilitación en pacientes que van a ser llevados a esta cirugía.
Palabras clave: reconstrucción de pared abdominal, Complicaciones de cirugía, Factores de Riesgo, Reparación de hernia ventralObjective: to evaluate the literature on risk factors with greater strength of association for complications of abdominal wall reconstruction surgery. Methods: A systematized review was made in the literature looking at different databases, studies performed on patients with risk factors for complications of abdominal wall reconstruction surgery. Literature was included since 2000. Results: after having entered the terms Mesh and Desc, the application of inclusion and exclusion criteria, qualify the literature and eliminate duplicates, 19 articles were chosen for systematized review. Conclusions: There are some risk factors described in the literature (Diabetes, smoking, obesity, concomitant surgery, Sarcopenia) that could increase the rate of complications in this surgery. Studies should be conducted trying to control these variables to optimize the prehabilitation in patients who are going to be taken to this surgery
Factores de riesgo asociados a complicaciones en cirugía de reconstrucción de pared abdominal: revisión sistematizada de la literatura
Introducción: Los costos generados por la corrección de las eventraciones abdominales no solo se deben a técnicas quirúrgicas más complejas y el uso de materiales protésicos costosos. La evolución de estas técnicas quirúrgicas ha permitido tener procedimientos con reconstrucciones más fisiológicas, pero con una mayor tasa de complicaciones.
Objetivo: Evaluar la literatura sobre los factores de riesgo con mayor fuerza de asociación para complicaciones de cirugía de reconstrucción de pared abdominal. Métodos: Se realizó una revisión sistematizada en la literatura buscando estudios realizados en pacientes con factores de riesgo para complicaciones de cirugía de reconstrucción de pared abdominal. Resultados: El rango de complicaciones es muy amplio, hay series que muestran tasas tan bajas como 1,94% y otras que llegan hasta el 36%. Las complicaciones infecciosas del sitio operatorio son las más frecuentes llegando a alcanzar hasta un 57% del global de las complicaciones. En orden descendente las siguientes son: Complicaciones gastrointesinales (19%), dolor (17%) Hematologicas (8%), cardiacas (8%), pulmonares (6%), hepatobiliares (2%). Los factores de riesgo más frecuentes corresponden a: diabetes mellitus, tabaquismo, obesidad, cirugía concomitante y sarcopenia. Conclusiones: Existen algunos factores de riesgo descritos en la literatura que podrían aumentar la tasa de complicaciones en esta cirugía. Se deben realizar estudios tratando de controlar estas variables para poder optimizar la prehabilitación en pacientes que van a ser llevados a esta cirugía.
Palabras clave: reconstrucción de pared abdominal, Complicaciones de cirugía, Factores de Riesgo, Reparación de hernia ventralObjective: to evaluate the literature on risk factors with greater strength of association for complications of abdominal wall reconstruction surgery. Methods: A systematized review was made in the literature looking at different databases, studies performed on patients with risk factors for complications of abdominal wall reconstruction surgery. Literature was included since 2000. Results: after having entered the terms Mesh and Desc, the application of inclusion and exclusion criteria, qualify the literature and eliminate duplicates, 19 articles were chosen for systematized review. Conclusions: There are some risk factors described in the literature (Diabetes, smoking, obesity, concomitant surgery, Sarcopenia) that could increase the rate of complications in this surgery. Studies should be conducted trying to control these variables to optimize the prehabilitation in patients who are going to be taken to this surgery
A preliminary study on self sensing composite structures with carbon nanotubes
Dynamic measurements on carbon nanotube (CNT) multiscale glass fiber reinforced polymers (GFRPs) were performed to assess the usage of self-sensing composite structures in vibration environment. To achieve that purpose, a composite cantilever beam was tested in static and dynamic conditions. Applied strain was measured by means of strain gauges mounted on the tested specimen. Static measurements were performed to investigate linearity and repeatability of the CNT sample response. The dynamic behavior was evaluated with step sine excitation at different forcing frequencies. Preliminary results finally proved the validity and the applicability of carbon nanotubes composites to measure dynamic forcing and vibration
Crack propagation monitoring on bonded joints with novel carbon nanotube doped adhesive films
An investigation on fatigue crack propagation on bonded joints has been carried out. For that
purpose, a novel carbon nanotube (CNT) doped adhesive film has been used, exploiting CNT
exceptional electrical sensitivity for fatigue damage monitoring. Single lap shear fatigue tests
have been conducted at 7 kN load and 10 Hz frequency while the electrical response of the
joints has been measured by means of voltage acquisition. In addition, crack length has been
also monitored by optical analysis using a microscope camera. A clear correlation between the
electrical response and the crack length has been highlighted during fatigue tests. In particular,
it is possible to distinguish three different regions: the first, with no crack initiation and, thus, a
stable measured electrical resistance; the second, where crack initiation and a first propagation
take place, characterized by a slight increase of the electrical resistance; the third, including the
final propagation to failure, where a sharp increase of the electrical resistance is observed.
Moreover, the number of cycles to failure is not affected negatively by the addition of CNTs.
Thus, CNT doped adhesive film capability to detect crack initiation and propagation has been
demonstrated, proving their huge potential for Structural Health Monitoring (SHM) purposes
Investigación, reflexión y acción de la realidad socio-educativa a principios del siglo XXI : vol. III
Consciente de la importancia de la investigación educativa para promover las transformaciones que permitan ofrecer a la sociedad nacional e internacional una educación pertinente y relevante que al mismo tiempo, contribuya con el desarrollo humano, en febrero del 2011 y en el marco de la celebración del 30 aniversario de su fundación, el Instituto de Investigación en Educación (INIE) organiza el II Congreso Internacional de Investigación Educativa: Su Incidencia en la Realidad Social. Los aportes presentados durante este II Congreso Internacional de Investigación Educativa, se han recopilado en la publicación del libro digital: Investigación, reflexión y acción de la realidad socio-educativa a principios del siglo XXI. Estos trabajos tienen por objetivo ofrecer propuestas para repensar la educación y los procesos educativos que se desarrollan en las aulas, así como valorar la importancia de realizar las transformaciones que se requieren a partir de los resultados de las investigaciones
The comparative responsiveness of Hospital Universitario Princesa Index and other composite indices for assessing rheumatoid arthritis activity
Objective To evaluate the responsiveness in terms of correlation of the Hospital Universitario La Princesa Index (HUPI) comparatively to the traditional composite indices used to assess disease activity in rheumatoid arthritis (RA), and to compare the performance of HUPI-based response criteria with that of the EULAR response criteria. Methods Secondary data analysis from the following studies: ACT-RAY (clinical trial), PROAR (early RA cohort) and EMECAR (pre-biologic era long term RA cohort). Responsiveness was evaluated by: 1) comparing change from baseline (Delta) of HUPI with Delta in other scores by calculating correlation coefficients; 2) calculating standardised effect sizes. The accuracy of response by HUPI and by EULAR criteria was analyzed using linear regressions in which the dependent variable was change in global assessment by physician (Delta GDA-Phy). Results Delta HUPI correlation with change in all other indices ranged from 0.387 to 0.791); HUPI's standardized effect size was larger than those from the other indices in each database used. In ACT-RAY, depending on visit, between 65 and 80% of patients were equally classified by HUPI and EULAR response criteria. However, HUPI criteria were slightly more stringent, with higher percentage of patients classified as non-responder, especially at early visits. HUPI response criteria showed a slightly higher accuracy than EULAR response criteria when using Delta GDA-Phy as gold standard. Conclusion HUPI shows good responsiveness in terms of correlation in each studied scenario (clinical trial, early RA cohort, and established RA cohort). Response criteria by HUPI seem more stringent than EULAR's
Delayed colorectal cancer care during covid-19 pandemic (decor-19). Global perspective from an international survey
Background
The widespread nature of coronavirus disease 2019 (COVID-19) has been unprecedented. We sought to analyze its global impact with a survey on colorectal cancer (CRC) care during the pandemic.
Methods
The impact of COVID-19 on preoperative assessment, elective surgery, and postoperative management of CRC patients was explored by a 35-item survey, which was distributed worldwide to members of surgical societies with an interest in CRC care. Respondents were divided into two comparator groups: 1) ‘delay’ group: CRC care affected by the pandemic; 2) ‘no delay’ group: unaltered CRC practice.
Results
A total of 1,051 respondents from 84 countries completed the survey. No substantial differences in demographics were found between the ‘delay’ (745, 70.9%) and ‘no delay’ (306, 29.1%) groups. Suspension of multidisciplinary team meetings, staff members quarantined or relocated to COVID-19 units, units fully dedicated to COVID-19 care, personal protective equipment not readily available were factors significantly associated to delays in endoscopy, radiology, surgery, histopathology and prolonged chemoradiation therapy-to-surgery intervals. In the ‘delay’ group, 48.9% of respondents reported a change in the initial surgical plan and 26.3% reported a shift from elective to urgent operations. Recovery of CRC care was associated with the status of the outbreak. Practicing in COVID-free units, no change in operative slots and staff members not relocated to COVID-19 units were statistically associated with unaltered CRC care in the ‘no delay’ group, while the geographical distribution was not.
Conclusions
Global changes in diagnostic and therapeutic CRC practices were evident. Changes were associated with differences in health-care delivery systems, hospital’s preparedness, resources availability, and local COVID-19 prevalence rather than geographical factors. Strategic planning is required to optimize CRC care