ABSTRACT
Problem: Intensity in endurance training is important for improving race time; its optimal handling in amateur runners has not been extensively studied. The polarized training intensity distribution (TID) model emerges as a possibility to reduce race time; however, effect of this model remains to be demonstrated compared to other TID models. Objective: The objective of this study is to explore the current state of the evidence and its the gaps, according to the effect of the polarized TID model on race time in amateur runners compared to other TID models. Method: A scoping review without date restrictions was carried out in PubMed, EBSCO, SciELO, LILACS, and Google Scholar. Randomized controlled studies, quasi-experimental studies, and case studies, which comprise polarized TID model in amateur runners on race time, were include. Results: Five studies evaluated the effect on running time using the polarized TID model compared to other models in amateur runners; four of them did not show differences between groups in the race times in two, five, and ten km. Only one study showed significant diferences in the race time at 21 km. Conclusions: The model with polarized TID did not show significant differences in race time compared to other models, except for a case report in which the polarized TID was higher by 21 km compared to the threshold TID: 1 hour. 20 min. 22 seconds and 1 hour. 26 min. 34s, respectively. The scarce evidence found, the heterogeneity in the distances in the evaluated race time, the distribution of zones in the same TID, the duration of the interventions, and the monitoring of the loads, are the main limitations found in the studies. The polarized TID could contribute to adherence, lower perception of effort, and injury prevention. However, this must be tested in future studies.
Problema: La intensidad en el entrenamiento de la resistencia es importante para mejorar el tiempo de carrera; su manipulación óptima en corredores recreativos no ha sido estudiada ampliamente. El modelo de distribución de intensidad del entrenamiento (DIE) polarizado emerge como posibilidad para reducir el tiempo de carrera. Sin embargo, falta demostrar su efecto comparado con otros modelos de DIE. Objetivo: Explorar el estado actual de la evidencia científica y sus vacíos respecto al efecto del modelo de DIE polarizado sobre el tiempo de carrera en corredores recreativos, en comparación con otros modelos de DIE. Método: Se realizó una revisión de alcance sin restricción de fechas en PubMed, EBSCO, SciELO, LILACS y Google Scholar. Se incluyeron estudios controlados aleatorios, estudios cuasiexperimentales y estudios de caso, que tuvieran como DIE el modelo polarizado en corredores recreativos sobre el tiempo de carrera. Resultados: Cinco estudios evaluaron el efecto en el tiempo de carrera usando el modelo de DIE polarizado comparado con otros modelos en corredores recreativos; cuatro de ellos no mostraron diferencias entre grupos en los tiempos de carrera en dos, cinco y diez km. Solo un estudio mostró diferencias significativas en el tiempo de carrera en 21 km. Conclusiones: El modelo con DIE polarizado no mostró diferencias significativas en el tiempo de carrera comparado con otros modelos, a excepción de un reporte de caso en el cual la DIE polarizado fue superior en 21 km comparado la DIE umbral: 1 hora. 20 min. 22 s y 1 hora. 26 min. 34 s, respectivamente. La escasa evidencia encontrada, la heterogeneidad en las distancias en el tiempo de carrera evaluado, la distribución de zonas en una misma DIE, la duración de las intervenciones y la monitorización de las cargas son las principales limitaciones encontradas en los estudios. La DIE polarizado podría contribuir a la adherencia, a una menor percepción del esfuerzo y a la prevención de lesiones. No obstante, esto debe ser probado en estudios futuros.
Subject(s)
Exercise , Fitness Centers , Exercise Movement Techniques , Endurance Training , Perception , Running , Track and Field , High-Intensity Interval Training , ForecastingABSTRACT
Objective To detect the expression of cyclooxygenase(COX) in human gastric cancer cell lines and its subcellular location of the isoforms. Methods Immunohistochemistry、RTPCR combined with laser scanning cofocal microscopy (LSCM) were used to investigate expression and distribution of COX. Results Positive staining of COX2 and COX1 protein was seen in human gastric cancer cell line MKN45、SGC7901 and AGS. However, the COX2 staining was absent and COX1 staining was weak in MGC803; though their mRNA in all the four cell lines. When compared to COX1,COX2 showed a stronger signal at both protein and mRNA levels of the gastric cancer cell lines, which was confirmed by double labeling and LSCM. The quantitative analysis of fluorescein intensity indicated the pixel intensity peak of COX2 reached 50～70, while COX1 only 10. LSCM also showed that COX2 was both cytoplasmic and nuclear envelope staining but COX1 only in cytoplasm. Conclusions In human gastric cancer, there is stronger expression of COX2 than COX1, and different distribution of the two isoforms implies their distinct roles in cell function.
ABSTRACT
Purpose: To analyze the effect of the intraarticufar contact of the temporomandibular joint ( TMJ ) on three dimensional nonlinear simulation of human TMJ forces in order to simulate the distribution and transfer of TMJ forces more realistically and logically. Materials and Methods: Combining helical CT scanning technology with three dimensional finite element method, together with Auto CAD software, three dimensional nonlinear finite element models were developed in vivo for comparison with the changes in the stress within the TMJ in different contact conditions. Results: The stresses on the surfaces of articular disc and condyle in the finite element models with contact elements between the disc and condyle were mainly distributed on their anterior and medial regions, and the stresses on other regions were relatively smaller. But, the stresses of those models without contact element were mainly distributed on their midposterior and medial aspacts. Moreover, the stress values were higher. When the friction coefficient was in the range of 0 0.15, the distribution extent and magnitude of the contact stress between the disc and the condyle in the TMJ were completely same. Meanwhile, the surface stresses on the disc and the condyle were nearly coincident in three ways of disc condyle contact, which were no friction contact, rigid contact and elastic contact. Conclusion: In the issue of disc condyle contact of simulating TMJ forces with three dimensional nonlinear method, the stress distribution in the joint with complete contact relationship between the disc and the condyle conforms more to the physiological condition. The lower friction coefficient ( 0 0.15 ) in the TMJ and various contact patterns between the disc and condyle had no evident influence on the stress distribution in the TMJ. Three dimensional nonlinear analysis for the forces in the TMJ might be more realistic and reasonable because of contact simulation among various structures within the TMJ.