共查询到20条相似文献,搜索用时 0 毫秒
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自体腓骨骨栓内固定加股方肌肌蒂骨瓣治疗陈旧性股骨颈骨折 总被引:1,自引:0,他引:1
股骨颈骨折的治疗仍被视为难题,尤其是陈旧性股骨颈骨折,至今疗效仍不理想。笔者从1980年以来,设计应用自体腓骨骨栓内固定加股方肌肌蒂骨瓣植骨的方法治疗陈旧性股骨颈骨折,随访5年以上的有26例,取得较好远期疗效。强调良好的复位和可靠的内固定以及尽早足够的恢复股骨头的血供是治疗股骨颈骨折的三要素。笔者介绍了手术方法,并对这种治疗方法的优越性作了讨论。 相似文献
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Heating around intravascular guidewires by resonating RF waves 总被引:4,自引:0,他引:4
Konings MK Bartels LW Smits HF Bakker CJ 《Journal of magnetic resonance imaging : JMRI》2000,12(1):79-85
We examined the unwanted radiofrequency (RF) heating of an endovascular guidewire frequently used in interventional magnetic resonance imaging (MRI). A Terumo guidewire was partly immersed in an oblong saline bath to simulate an endovascular intervention. The temperature rise of the guidewire tip during an FFE sequence [average specific absorption rate (SAR) = 3.9 W/kg] was measured with a Luxtron fluoroscopic fiber. Starting from 26 degrees C, the guidewire tip reached temperatures up to 74 degrees C after 30 seconds of scanning. Touching the guidewire may cause sudden heating at the point of contact, which in one instance caused a skin burn. The excessive heating of a linear conductor like the guidewire can only be explained by resonating RF waves. The capricious dependencies of this resonance phenomenon on environmental factors have severe consequences for predictability and safety guidelines. 相似文献
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Raja Muthupillai Phillip J. Rossman David J. Lomas James F. Greenleaf Stephen J. Riederer Richard L. Ehman 《Magnetic resonance in medicine》1996,36(2):266-274
We describe a phase contrast based MRI technique with high sensitivity to cyclic displacement that is capable of quantitatively imaging acoustic strain waves in tissue-like materials. A formalism for considering gradient waveforms as basis functions to measure arbitrary cyclic motion waveforms is introduced. Experiments with tissue-like agarose gel phantoms show that it is possible to measure small cyclic displacements at a submicron level by an appropriate choice of the applied gradient basis function and to use this capability to observe the spatial and temporal pattern of displacements caused by acoustic strain waves. The propagation characteristics of strain waves are determined by the mechanical properties of the media. It is therefore possible to use this technique to noninvasively estimate material properties such as elastic modulus. 相似文献
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Cullis IG 《Journal of the Royal Army Medical Corps》2001,147(1):16-26
The paper defines and describes blast waves, their interaction with a structure and its subsequent response. Explosions generate blast waves, which need not be due to explosives. A blast wave consists of two parts: a shock wave and a blast wind. The paper explains how shock waves are formed and their basic properties. The physics of blast waves is non-linear and therefore non-intuitive. To understand how an explosion generates a blast wave a numerical modelling computer code, called a hydrocode has to be employed. This is briefly explained and the cAst Eulerian hydrocode is used to illustrate the formation and propagation of the blast wave generated by a 1 kg sphere of TNT explosive detonated 1 m above the ground. The paper concludes with a discussion of the response of a structure to a blast wave and shows that this response is governed by the structures natural frequency of vibration compared to the duration of the blast wave. The basic concepts introduced are illustrated in a second simulation that introduces two structures into the blast field of the TNT charge. 相似文献
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Traumatic "myocarditis" or "myocarditis" in trauma 总被引:1,自引:0,他引:1
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Pathogenesis of pulmonary edema caused by blast waves] 总被引:1,自引:0,他引:1
I Cernak J Savi? B Mrsulja B Durici? 《Vojnosanitetski pregled. Military-medical and pharmaceutical review》1991,48(6):507-514
In the study of pathogenetic mechanisms of pulmonary edema to blast wave generated by detonation of the aerosol explosive in the open air, the dynamics of changes of the eicosanoid contents, the products of the energy metabolism as well as the glucose metabolism in the lung tissue of sheep have been examined. On the basis of data from the literature as well as own results the authors have given the original scheme of possible mechanisms of pulmonary edema caused by effects of the blast wave. 相似文献
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L. Barritault J. N. Rimbert J. F. Hirsch A. Pierre-Kahn J. Lacombe A. Zouaoui J. Mises V. Gabersek 《European journal of nuclear medicine and molecular imaging》1980,5(6):511-514
By measuring cerebral blood volume (CBV) and intracranial pressure (ICP) variations at the same running time during sleep, it has been demonstrated that the ICP wave which appears during the REM sleep in hydrocephalic infants is produced by intracerebral vaso-dilatation. Nine infants with stabilized hydrocephalus were investigated by non-invasive means: REM phases were distinguished with the usual polysomnographic electrodes. Intracranial pressure was measured with a fontanel palpation transducer and CBV variations were obtained by recording 99mTc activity at the head level after in vivo labelling or red cells with 99mTc — pertechnetate. The timeactivity curves, obtained from regions of interest and selected on the sequential radioisotope images, show that an increased ICP wave, occurring during the REM period, is related to a simultaneous increase in the blood volume, limited to the cerebral sector and not to the area of the external carotid artery.Presented at the Third European Congress of Nuclear Medicine, May 15–18, 1979, Karlovy-Vary 相似文献
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