RESUMEN
The interaction forces between dust grains in a flowing plasma are strongly modified by the formation of ion wakes. Here, we study the interparticle forces mediated by ion wakes in the presence of a strong magnetic field parallel to the ion flow. For increasing magnetic flux densities a continuous decay of the interaction force is observed. This transition occurs at parameters, where the ion cyclotron frequency starts to exceed the ion plasma frequency, which is in agreement with theoretical predictions. The modification of the interparticle forces is important for the understanding of the structure and dynamics of magnetized dusty plasmas.
RESUMEN
INTRODUCTION: The purpose of this study was to compare the functional results using two different types of reconstruction of the anterior cruciate ligament. MATERIAL AND METHODS: A retrospective comparison of 34 patients operated with a fascia lata graft and 26 patients operated with a bone-patellar tendon-bone graft. The patients were evaluated twice with a postoperative Lysholm score, a preoperative and postoperative Tegner score, and a postoperative knee-laxity test. RESULTS: The Lysholm scores after the first (P = 0.07) and second (P = 0.29) postoperative control showed no difference between the two groups. There was no difference between the preoperative and postoperative Tegner scores of the two groups (P = 0.42). A total of 27 patients out of 60 practiced sports or had knee-straining work postoperatively at the same level as preoperatively. No difference was found between the two groups when comparing the knee-laxity tests (P = 0.12). DISCUSSION: This study did not find any difference in the final functional results when comparing the two operation techniques. Almost half of the patients can expect a return to sports at a preinjury level.