Fluoroscopic bone fragment tracking for surgical navigation in femur fracture reduction by incorporating optical tracking of hip joint rotation center

A new method for fluoroscopic tracking of a proximal bone fragment in femoral fracture reduction is presented. The proposed method combines 2-D and 3-D image registration from single-view fluoroscopy with tracking of the head center position of the proximal femoral fragment to improve the accuracy of fluoroscopic registration without the need for repeated manual adjustment of the C-arm as required in stereo-view registrations. Kinematic knowledge of the hip joint, which has a positional correspondence with the femoral head center and the pelvis acetabular center, allows the position of the femoral fragment to be determined from pelvis tracking. The stability of the proposed method with respect to fluoroscopic image noise and the desired continuity of the fracture reduction operation is demonstrated, and the accuracy of tracking is shown to be superior to that achievable by single-view image registration, particularly in depth translation.     

Conductive polymer patterned media fabricated by diblock copolymer lithography for scanning multiprobe data storage

A conductive polymer dot pattern has been fabricated as a patterned medium using diblock copolymer lithography (DCL) for scanning multiprobe data storage systems (SMDSSs). DCL can easily provide a higher dots pattern density than that obtained using electron beam lithography. For DCL, the microphase-separated structure of polystyrene-block-polymethylmethacrylate is utilized. Then, the closed dot pattern of polyaniline (PANI) with a center to center distance of adjacent dots of 30?nm is fabricated by DCL. Electrical modification experiments of the fabricated PANI dots are demonstrated using scanning probe microscopy (SPM). As a result, the conductivities of the modified dots are selectively changed by applying modification voltages with the tip of the SPM probe. Recording on the conductive polymer with 30?nm pitch at the minimum can be demonstrated, which corresponds to a recording density of ～700?Gbits?inch(-2). These results show that the conductive polymer patterned medium has the potential ability to achieve high-density recording for SMDSSs.     

Micromachined Si cantilever arrays for parallel AFM operation

Silicon cantilever arrays with a very small pitch for parallel AFM operations were studied. We fabricated 1x104 in eight groups and 1x30 Si probe arrays and produced a smaller pitch (15 μm) between probe tips by using Si anisotropic etching with a vertical wall shaped oxide mask. The vertical controls of Si probes were able to operate individually or in a group by integrating electrostatic actuators into the cantilevers of the probes. The fabricated Si cantilever arrays showed reasonable dynamic characteristics for the probe cantilever and reliable parallel operation of AFM.     

Cloning and sequencing of kojibiose phosphorylase gene from Thermoanaerobacter brockii ATCC35047

A gene encoding kojibiose phosphorylase was cloned from Thermoanaerobacter brockii ATCC35047. The kojP gene encodes a polypeptide of 775 amino acid residues. The deduced amino acid sequence was homologous to those of trehalose phosphorylase from T. brockii and maltose phosphorylases from Bacillus sp. and Lactobacillus brevis with 35%, 29% and 28% identities, respectively. Kojibiose phosphorylase was efficiently overexpressed in Escherichia coli JM109. The DNA sequence of 3956 bp analyzed in this study contains three open reading frames (ORFs) downstream of kojP. The four ORFs, kojP, kojE, kojF, and kojG, form a gene cluster. The amino acid sequences deduced from kojE and kojF are similar to those of the N-terminal and C-terminal regions of a sugar-binding periplasmic protein from Thermoanaerobacter tengcongensis MB4. Furthermore, the amino acid sequence deduced from kojG is similar to that of a permease of the ABC-type sugar transport systems from T. tengcongensis MB4. Each of three amino acid substitutions, D362N, K614Q and E642Q, caused a complete loss of kojibiose phosphorylase activity. These results suggest that D362, K614 and E642 play an important role in catalysis. Another mutation, D459N, increased K(m) values for kojibiose (7-fold that for the wild type), beta-G1P (11-fold) and glucose (7-fold), whereas K(m) for inorganic phosphate was minimally affected by this mutation, suggesting that D459 may be involved in the binding to saccharides.     

Antagonistic effect of the Ainu-selected traditional beneficial plants on the transformation of an aryl hydrocarbon receptor

Transformation of an aryl hydrocarbon receptor (AhR) is the initial step to express the multiple toxicity of halogenated and polycyclic aromatic hydrocarbons (HAHs and PAHs) including dioxins. Therefore, it has been suggested that suppression of the transformation induced by HAHs and PAHs leads to reduce their toxicological effects. In this study, the antagonistic effect of 110 indigenous plants (192 plant parts) used as medicine and/or food by the Ainu on the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced AhR transformation was investigated. Of these, a stalk of Aralia elata (Miq.) Seemann and a bark of Fraxinus mandshurica Rupr. var. japonica Maxim. exhibited the strong antagonistic effect in a dose-dependent manner. An antioxidative activity and polyphenol content were also measured, and the strong correlation (r= 0.96) between these two parameters could be confirmed. However, correlation coefficients of the antagonistic effect of 192 extracts compared to their antioxidative activity and polyphenol content were 0.17 and 0.20, respectively. These results suggest that the Ainu-selected traditional beneficial plants are useful source for findings of novel AhR antagonists, and the antagonistic activity of these plants may be independent on their antioxidative activity and polyphenol content. PRACTICAL APPLICATION: Our findings lead to discovery of the valuable plants used by the Ainu and the novel active compounds useful for human's life, and furthermore, may contribute to the development of new medicines and functional foods.     

Engineered Heat-Straightening Repairs: A Case Study

The goal of this study was twofold: (1) To demonstrate that engineered heat straightening is a viable alternative for the repair of damaged steel bridge girders; and (2) to illustrate how the latest results of research and development can be implemented for heat-straightening repairs. The bridge chosen for repair crosses over I-10 in Louisiana, just east of Lake Charles. Working with personnel from the Louisiana Department of Transportation and Development, the bridge was repaired during August 1998. A fascia noncomposite beam had been impacted, and the bottom flange was displaced 0.43 m (17 in.). The repair was designed by the writers and implemented in conjunction with Louisiana Department of Transportation and Development personnel. Described in this paper are the design of the repair, including assessment of damage, selection of heating patterns, development of jacking restraint locations and magnitudes, and heating sequences; the step-by-step implementation; a cost comparison; and a discussion of lessons learned. It is concluded that heat straightening is an effective alternative for repairing damaged steel bridges, when implemented with proper engineering design.     

Crack propagation behavior of cermets and cemented carbides under repeated thermal shocks by the improved quench test

In this study, an improved quench testing method for thermal shock resistance has been proposed. Repeated thermal shock tests were performed on cemented carbides to show the advantages of the new proposed method that would enable us to estimate an intrinsic relationship between the crack propagation rate and the stress intensity factor under repeated thermal shocks. The cyclic thermal fatigue crack propagation behavior and fracture toughness values were shown to be independent of the specimen heights and the cooling media employed. We then evaluated the thermal crack propagation behavior for cermets and cemented carbides by using this method, and discussed the differences between both materials in the crack growth behavior on the basis of their microstructures.     

Mechanical properties of ultrahigh-molecular-weight polyethylene fiber-reinforced PE composites

Three types of high-strength polyethylene (PE) fiber-reinforced composite sheets were made by compression molding at the vicinity of melting point of the fiber. Sheet I was molded from only PE fibers. Sheets II and III were prepared by the compression molding of PE fiber with conventional high- and low-density polyethylene films, respectively. The mechanical properties, thermal behavior, and morphologies of the sheets have been investigated and compared with each other. The tensile strength and elastic modulus of sheet III are 660 MPa and 14 GPa, respectively, which were 60 and 30 times higher than those of typical low-density PE film. Although the elastic modulus of sheet III is 6 GPa less than that of sheet II, the tensile strength of 660 MPa is highest in the three types of sheets prepared in this study. The mechanical properties of sheets II and III were about half of predicted theoretical ones. It was concluded that the interfacial adhesion between PE fiber and PE matrix was an important factor to improve the mechanical properties of this PE sheet. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1431–1439, 1998