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The purpose of this study was to investigate the location of the centre of resistance (CRe) for the nasomaxillary complex by the use of finite element analysis. A three-dimensional finite element model of the craniofacial complex, consisting of 2918 nodes and 1776 elements, was used for displacement analyses. Anteriorly and inferiorly directed forces of 9·8 N were applied at five different levels, parallel and perpendicular to the functional occlusal plane, respectively. For each loading condition, horizontal and vertical displacements of eight anatomic points in the complex and on the maxillary dentition were analysed. The complex exhibited an almost translatory displacement of approximately 1·0 µm in the forward direction when the horizontal force was applied at a point on the horizontal plane, passing through the superior ridge of the pterygomaxillary fissure, whereas the complex experienced clockwise or counter clockwise rotation when the forces were applied at the remaining levels. Furthermore, the downward forces produced anteriorly upward, or posteriorly upward rotation. However, the force applied at a point on the vertical plane passing through the posterior wall of the pterygomaxillary fissure, produced almost equal displacements of approximately 6·0 µm in an inferior direction for all the anatomic points. It is suggested that CRe of the nasomaxillary complex is located on the posterosuperior ridge of the pterygomaxillary fissure, registered on the median sagittal plane.

The study of fast electron spectrum optimization by suppression of preformed plasma in fast ignition targets is presented in this work. Integrated fast-electron spectra for electron energies below 3 MeV-the energy range responsible for core heating-are compared for different preformed plasma conditions. The pulse contrast (the ratio of peak-to-pedestal laser intensities) is compared for 10 8 , 10 9 and 10 11 conditions at constant laser energy (~500 J), pulse duration (2 ps), spot size (30% encircled energy on 50 µm diameter) and laser intensity (around 1 × 10 19 W cm −2 ). The best electron spectrum optimization, consisting of maximized electron number for energies below 3 MeV was obtained with 14 µm thick cone targets. The energy coupling efficiency from heating laser to core plasma, assuming typical core plasma parameters, was estimated to be 2%, although 0.37% was obtained with previous conditions with poor pulse contrast and a 7 µm thick cone target.

F or many years, the standard operation for varices of great saphenous veins (GSV) was the selective stripping, stab avulsion and sclerotherapy of the varicosities. 1) Rec ently, however, endovenous laser and radio-frequency ablation of GSV have become new standard techniques. In both techniques, the below-knee GSV is usually preserved in order to prevent nerve injury. As a result, reflux in the below-knee saphenous vein often persists after the operation.The aim of this study was to analyze the influence of persistent below-knee saphenous reflux and incompetent calf perforating veins on venous function after stripping. MaterIals and MethodsFrom September 2007 to October 2008, 939 limbs (627 patients) were treated at Hiroshima Teishin Hospital. During this period, 131 limbs (131 patients) with varicosities of one side of the GSV were analyzed for this study.The patients were interviewed before surgery, one month after the operation, and one year after the operation. The venous filling index (VFI: normal range is lower than 2.0 ml/sec) was measured by air plethysmography, and persistent below-knee saphenous reflux was evaluated by duplex scanning. Persistent reflux was diagnosed when the reflux time was over 0.5 seconds using Persisting incompetent great saphenous vein (GSV) below the knee and residual incompetent perforating veins (IPV) are often found after selective stripping of GSV from the groin to upper calf. The aim of this study is to evaluate the venous function when the calf GSVs or calf perforating veins are incompetent after stripping surgery. One hundred-thirty-one limbs were treated by stripping from the groin to upper calf with stab avulsion or sclerotherapy of varices. One month and twelve months after surgery, the patients were examined clinically to establish the extent of persisting varices by duplex ultrasonography and air-plethysmography. Venous filling index (VFI) was a little higher in those who had residual calf GSV reflux 12 months later; it was also higher in the group with incompetent perforating veins than the group without. The chief complaints were found to have improved in all groups. The findings suggest that removal of the saphenous vein below the knee is not necessary, but it is important to take care of the incompetent perforating veins. (*English Translation of Jpn J Phlebol 2011; 22: 239-244.)

A short and high-intensity neutron pulse can be produced efficiently by using photonuclear reactions caused by Bremsstrahlung hard X-rays in a lase-irradiated high-Z target. The efficient and repetitive neutron generation was demonstrated with the combination of 1 Hz, 0.5 J, 25 fs, 5 × 10 19 W/cm 2 laser pulses and a rotating tungsten disc targe. Here we applied double laser pulse irradiation scheme to increase the neutron generation efficiency. The first low-intensity laser pulse produces a lon-scale unde-critical-density plasma on the tungsten target surface prior to the second pulse irradiatio. High energy electrons above the ponderomotive scaling value are accelerated by the second hig-intensity pulse in the preformed plasm, this results in the increment of hard X-ray photons and photonuclear neutron. 3.5 × 10 4 neutron/pulse was obtained with optimized laser irradiation conditions.