ABSTRACT
Objective To explore the effects of military stress on memory function in battlefield environment confined intensive training of peace-keeping soldiers.Methods 41 peace-keeping soldiers were chosen as the research objects.They were tested the memory function,respectively after they trained intensely in the domestic and in Sudan for five months.The memory function included verbal memory:WHO-UCLA auditory verbal learning test (immediate recall,the insert test,the short time delay memories,long delayed recall,long delayed recognition,visual memory) using the Rey Ostereitb Complex Figure (graphics copy and graphic delayed recall).Results The peace-keeping soldiers got lower scores in the insert tested(4.59±2.03) and graphics copy(35.85± 0.36) than in the domestic (4.85 ± 2.21,35.71 ± 0.46,P＞ 0.05),but there was no significant difference.They got lower scores in the immediate recall (41.68±9.87),the short time delay memories (9.27±2.77),long delayed recall (9.12±2.99),long delayed recognition (27.56± 1.70),and graphic delayed recall (16.90± 6.16) than those in the domestic(51.68±8.63,11.73±2.15,12.24± 1.96,29.00± 1.43,23.15±7.16,P＜0.01),and the difference was statistically significant.Conclusion The peace-keeping soldiers battlefield environment stress has a certain effect on the soldiers' memory function.
ABSTRACT
<p><b>OBJECTIVE</b>Unstable intertrochanteric fractures (ITFs) are mostly treated by proximal femoral nail antirotation (PFNA), Inter-Tan, Asian Hip, and other new internal fixation devices. But for complex unstable fractures, such as crushed lateral wall of the greater trochanter, the loss of fixation point on lateral wall slightly reduces the fixing effect. This study aimed to compare the biomechanical strengths between reversed less invasive stabilization system (LISS) and PFNA for treatment of unstable ITFs.</p><p><b>METHODS</b>Forty synthetic femurs were used to simulate unstable ITFs in vitro and were fixed using the reversed LISS or PFNA. These fractures were divided into two groups depending on whether the lateral wall of the greater trochanter is intact or not (AO classification: 31-A2.3 and 31-A3.3, respectively). The load-displacement of femur, stiffness, ultimate load, and cyclic fatigue resistance were detected using an incremental load test and a dynamic fatigue test through an MTS 858 test system.</p><p><b>RESULTS</b>For both 31-A2.3 and 31-A3.3, the vertical sinking displacement (VSD) of the femoral head under 500 N load was insignificantly smaller after treatment with reversed LISS than with PFNA, and when the displacement was 5 mm, the femoral head bore insignificantly greater load. The fixation with reversed LISS resulted in greater axial stiffness of the femur but smaller ultimate load. During the same cycle in the dynamic fatigue test, the VSD was insignificantly smaller with the fixation of reversed LISS.</p><p><b>CONCLUSION</b>Reversed LISS and PFNA have similar biomechanical strength for unstable ITFs. This conclusion should be supported by additional large-size research on basic biomechanics and clinical application. This is the first comparative biomechanical study comparing reversed LISS and PFNA for unstable ITFs.</p>