DOES SIDE OF AMPUTATION AFFECT 200- AND 400-M RACE TIME IN SPRINTERS USING RUNNING-SPECIFIC PROSTHESES?

Current Paralympic guidelines for track events are generally based on level of amputation, not side of amputation. Since 200- and 400-m sprint races are performed in a counter clockwise direction, the effects of amputations side on sprint race performance in athletes with unilateral lower limb amputation should be investigated. Forty-five unilateral transtibial amputees participating in elite-level 200- and 400-m races were analysed from publicly available Internet broadcasts. For each athlete, official race time, and amputation side were determined. We found no significant difference in official race time between left and right side amputees during the 200- and 400-m sprint, indicating that sprint performance on a standard track in amputee athletes is not affected by amputation side

Newly developed data-matching methodology for oral implant surgery allowing the automatic deletion of metal artifacts in 3D-CT images using new reference markers: A case report

Patients: The patient was a 55-year-old woman with left upper molar free-end edentulism and 9 full cast metal crowns in her mouth. Three three-dimensional (3D) images were superimposed: a computed tomography (CT) image with the patient wearing the CT-matching template (CTMT) with six glass ceramic markers, which hardly generate any artifacts, on the template surface, and oral plaster model surfaces with and without CTMTs. Metal artifacts were automatically removed by a Boolean operation identifying unrealistic images outside the oral plaster model surface. After the preoperative simulation, fully guided oral implant surgery was performed. Two implant bodies were placed in the left upper edentulism. The placement errors calculated by comparing the preoperative simulation and actual implant placement were then assessed by a software program using the 3D-CT bone morphology as a reference. The 3D deviations between the preoperative simulation and actual placement at the entry of the implant body were a maximum 0.48 mm and minimum 0.26 mm. Those at the tip of the implant body were a maximum 0.56 mm and a minimum 0.25 mm. Discussion: In this case, the maximum 3D deviations at the entry and tip section were less than in previous studies using double CT. Conclusions: Accurate image fusion utilizing CTMT with new reference markers was possible for a patient with many metal restorations. Using a surgical guide manufactured by the new matching methodology (modified single CT scan method), implant placement deviation can be minimized in patients with many metal restorations

Combined analysis of microstructures within an annual ring of Douglas fir (Pseudotsuga menziesii) by dynamic mechanical analysis and small angle X-ray scattering

Dynamic mechanical analysis (DMA) and small angle X-ray scattering (SAXS) measurements of water-saturated wood of Douglas fir (Pseudotsuga menziesii) in the temperature range of 0 ℃ to 100 ℃ were focused to clarify microstructural changes within an annual ring. The following results were obtained. Thermal softening behavior caused by micro-Brownian motion of lignin was observed in both earlywood and latewood. The peaks of tanδ were found at around 95 ℃ for earlywood and at around 90 ℃ for latewood. These results suggested that the structures of lignin in the cell wall were different between earlywood and latewood. SAXS measurements of water-saturated earlywood and latewood in water were performed with precise temperature control. The scattering intensity increased with increasing temperature, indicating that the density of the matrix was reduced at higher temperature. One-dimensional SAXS intensity at the equator, which approximately represents cellulose microfibrils arrangement in the matrix, was intensively analyzed using the WoodSAS model. The result of this model fitting showed that the cellulose microfibril diameter of latewood was higher than that of earlywood. In addition, the value of interfibrillar distance decreased monotonically in the earlywood, while it decreased rapidly in the latewood from 60 ℃ to 90 ℃. The changes in the cellulose microfibril (CMF) diameter and the interfibrillar distance with increasing temperature between earlywood and latewood by SAXS measurement were different. The differences in CMF diameter and inter-fibril distance between earlywood and latewood measured by SAXS also support the hypothesis that lignin structure differs between earlywood and latewood based on the results of DMA measurements

Lipid-Protein Interactions in Double-Layered Two-Dimensional AQP0 Crystals

Lens-specific aquaporin-0 (AQP0) functions as a specific water pore and forms the thin junctions between fibre cells. We describe a 1.9 Å resolution structure of junctional AQP0, determined by electron crystallography of double-layered two-dimensional crystals. Comparison of junctional and non-junctional AQP0 structures shows that junction formation depends on a conformational switch in an extracellular loop, which may result from cleavage of the cytoplasmic N- and C-termini. In the centre of the water pathway, the closed pore in junctional AQP0 retains only three water molecules, which are too widely spaced to form hydrogen bonds with each other. Packing interactions between AQP0 tetramers in the crystalline array are mediated by lipid molecules, which assume preferred conformations. We could therefore build an atomic model for the lipid bilayer surrounding the AQP0 tetramers, and we describe lipid-protein interactions.Molecular and Cellular Biolog

LEG AND VERTICAL STIFFNESS OF TRANSFEMORAL AMPUTEES USING RUNNING-SPECIFIC PROSTHESES

Since running-specific prostheses (RSPs) emulate spring-like leg functions, human musculoskeletal system is often modelled as a spring-mass model. In the model, the leg (KM) and vertical stiffness (KM) is known to strongly influence running performance. The purpose of this study was to quantify the asymmetry in stiffness between the intact limbs and prosthetic limbs during sprinting. Eight sprinters with unilateral transfemoral amputation performed overground sprinting at maximum speed. & and Kw,t were calculated from vertical ground reaction force data in both the intact and prosthetic limbs. & was significantly greater in intact limbs than prosthetic limbs. Although there was no significant difference on Kvert, cohen's d of Kvert between legs was 1.28. Therefore KM might have potential significant difference

Reconstruction of the P2X2 Receptor Reveals a Vase-Shaped Structure with Lateral Tunnels above the Membrane

SummaryIn response to the intercellular messenger ATP, P2X receptors transfer various sensory information, including pain. Here we have reconstructed the structure of the P2X2 receptor at 15 Å resolution from more than 90,000 particle images, taken with a cryo-electron microscope equipped with a helium-cooled stage. This three-dimensional depiction, presumably in a closed state, revealed an elongated vase-shaped structure 202 Å in height and 160 Å in major diameter. The extracellular and transmembrane domains present a two-layered structure, in which a sparse outer layer surrounds a pore-forming inner density. The decreased diameter of a putative ion-conducting pathway at the middle of the membrane was considered to be the narrowest part of the pore, which has been predicted from electrophysiological studies. The sparse, extended structure of the P2X2 receptor indicates a loose assembly of subunits, which could be a basis for the activation-dependent pore dilation of P2X receptors

COMPARISON OF GROUND REACTION FORCES IN TWO RUNNING-SPECIFIC PROSTHESES (SPRINTER 1 E90 AND CHEETAH XTREME): A CASE STUDY

The purpose of this study was to describe the difference in ground reaction forces (GRF) between tvm different running-specific prostheses (RSPs) during maximal sprinting in a transfemoral amputee. One male sprinter performed maximal sprinting with two types of RSP (Sprinter 1E90 and Xtreme) on over 40 m runway with 7 force plates located halfway. Sprint velocity was found to be greater in the trials performed with Sprinter 1 E9O than with Xtreme. The peak VGRF, zero fore-aft shear and impulse of the anteriorposterior component of the GRF with PST limb differed among the two RSPs. These results suggest that the participant in this study would show the differences in variables influencing on the sprint velocity between two types of RSPs