共查询到20条相似文献,搜索用时 10 毫秒
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《EMC - Radiologie》2005,2(4):413-456
Imaging of normal and pathologic trachea at the thoracic and cervical levels is described extensively. Beside congenital abnormalities discovered in adulthood, acquired tracheal abnormalities are artificially divided in two subgroups. One group consists of diffuse abnormalities, with all but one diseases associated with a diffuse narrowing of the tracheal lumen. The other group comprises focal abnormalities that lead to tracheal stenoses of various lengths, with a postintubation stenosis as probably the most frequent cause, followed by tumours. The main modality for tracheal imaging is now multidetector-row spiral CT. This technique allows for faster volume coverage and higher spatial and temporal resolution. The improved spatial resolution impacts on both axial images and all reconstructions techniques that have become indispensable for interpretation of a vertical structure such as the trachea. Chest X-ray is no longer the frontline imaging technique. MRI has not yet reached all its potential as compared to CT. 相似文献
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《Science & Sports》2004,19(3):139-141
Introduction. – The rugby is a discipline requiring, in the same time, strength qualities and a high aerobic capacity for repeating intense exercises over 2 × 40 min.Synthesis of the facts. – Fourteen rugby players performed a maximal progressive test of journey (running) then two sequences of 40 min, respectively, to 60% and 80% of HRmax, interrupted with pushes on a yoke with constraint gauges. At 80% HRmax, the mean scrummaging force (1466 ± 244 N) was lower (P < 0.05) than at 60% HRmax (1523 ± 266 N).Conclusion. – The qualities of specific force are directly affected by the intensity of running. Therefore, there is a need to optimize the aerobic potential notably for the players of the first line directly concerned by the fight. 相似文献
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《Science & Sports》2002,17(5):263-265
Introduction – Finswimming is a new sport activity. The optimization of the leg’s propulsive action is fundamental to improve the performance. The aim of this work is to quantify finswimmer’s movements per race distances, using a kinematic analysis.Fact synthesis – Five elite finswimmers were video recorded during underwater races. The connections between the average velocity of stroke, frequency and range of finswimmers undulation are observed as a fonction of race distance.Conclusion – Finswimmers are shown to adjust and to stabilize instantaneously their movements in terms of race distance. 相似文献
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《Science & Sports》2002,17(6):312-314
Aim – To study the effects of endurance running (15 m/min during 20 min/day to 28 m/min during 1 h/d, 6 days/week during 12 weeks, corresponding to 62% of the VO2 max of the animals) or of a treatment by isoflavones (Soylife 100 : 400 μg j–1 g–1 of body weight during 12 weeks), either only or cumulated with running, on the osteopenia induced by castration in adult female rat.Results and discussion – Each one of these two treatment has a protective effect of the bone mineral density at the femoral total, diaphysaire and metaphysaire level. But contrary to what had been reported on the cumulated effects of long term endurance running and of a 17β-estradiol treatment 〚3〛, we did not note any additive effect of these two treatments. 相似文献
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Francesco Sardanelli Myriam G. Hunink Fiona J. Gilbert Giovanni Di Leo Gabriel P. Krestin 《European radiology》2010,20(1):1-15
Purpose
To provide an overview of evidence-based medicine (EBM) in relation to radiology and to define a policy for adoption of this principle in the European radiological community.Results
Starting from Sackett’s definition of EBM we illustrate the top-down and bottom-up approaches to EBM as well as EBM’s limitations. Delayed diffusion and peculiar features of evidence-based radiology (EBR) are defined with emphasis on the need to shift from the demonstration of the increasing ability to see more and better, to the demonstration of a significant change in treatment planning or, at best, of a significant gain in patient outcome. The “as low as reasonably achievable” (ALARA) principle is thought as a dimension of EBR while EBR is proposed as part of the core curriculum of radiology residency. Moreover, we describe the process of health technology assessment in radiology with reference to the six-level scale of hierarchy of studies on diagnostic tests, the main sources of bias in studies on diagnostic performance, and levels of evidence and degrees of recommendations according to the Centre for Evidence-Based Medicine (Oxford, UK) as well as the approach proposed by the GRADE working group. Problems and opportunities offered by evidence-based guidelines in radiology are considered. Finally, we suggest nine points to be actioned by the ESR in order to promote EBR.Conclusion
Radiology will benefit greatly from the improvement in practice that will result from adopting this more rigorous approach to all aspects of our work. 相似文献9.
《Science & Sports》2003,18(2):104-107
Aim. – Evaluate the knowledge of retail pharmacists of doping in sport and to describe their attitude in front to this phenomenon.Methods. – We proceeded by a prospective self-reported survey by postal mail with 105 retail pharmacists in Dakar which contains 299 pharmacies.Results. – We have received 68 answers. Only 10% of pharmacists know doping definition. They are 66% who think that senegalese sportsmen use doping products. They feel concerned with the problem of doping (81%) and 19% of them said having been contacted during these last 12 months for advice on doping products. They consider that doping is a kind of drug addiction and a public health problem. They estimated to 95% that the most effectiveness means of prevention would be to talk about side effects of doping products with the support of doctors.Conclusion. – This study which has to be extended must bring us to do big preventing actions. 相似文献
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《Science & Sports》2003,18(3):141-149
Purpose. – This study presents a new method for determining the resultant braking force during wheelchair displacement and investigates the respective effects of the level and the distribution of the system’s mass.Method and results. – A three-dimensional accelerometer was fixed directly under the seat of wheelchair and was used to measure the deceleration of the mass-and-wheelchair’s system. Three masses (50, 70 and 90 kg) were laid on a support in 3 positions corresponding to three distributions (10, 40 and 70%) of the system’s total mass upon the front casters. A series of 15 deceleration trials was performed for each of the 9 combinations. Statistical results showed that the system’s deceleration was mainly explained by the mass distribution upon the front casters (92%) and in the least by the system’s total mass (8%).Conclusion. – Considering the fore-and-aft movements of the subject’s centre of mass during wheelchair locomotion, the results of this study let us assume that the resultant braking force does not remain constant along the propulsion cycle. Moreover, the present method could be used to investigate the influence of wheelchair’s adjustments and floor’s characteristics on the resultant braking force. 相似文献
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《Science & Sports》2003,18(3):166-168
Aim. – Study was to asses the heart rate variability related to the physical practice intensity in post menopausal women.Method. – Time domain measurement of heart rate variability has been realised from the electrocardiogram at rest and during exercice in 3 groups of 6 women : untrained, active and trained. At rest, no significant difference betwen groups appears. But, in the standing position, RR interval and the dispersion around RR interval decrease in trained group only. During submaximal exercise, this dispersion is more elevated in active and trained groups.Conclusion. – Physical practice induces a higher response of sinus node to vagal modulation during standing position and submaximal exercise. 相似文献
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《Science & Sports》2001,16(6):323-325
Aim – Study was then to investigate hydration influence on exercise-induced GHh secretion.Methods and results – Seven healthy men underwent a submaximal rectangular cycling exercise for 30 minutes to 150 watts during two sessions. A first one without any water intake and a second one with ingestion of spring water corresponding to the volume of water lost during the first session. Plasma volume decrease was significantly higher during the first session (p < 0.05). Total GH secretion was significantly lower during this session (p < 0.05).Conclusion – A moderate dehydration decreases exercise-induced GH response. Thus, hypovolemia may exert a negative feed back on GH secretion, during exercise. 相似文献