Characteristics of laminated alloy films heads for high frequencyrecording

Excellent performance of laminated Fe-Si-Al alloy film heads is demonstrated in applications to high-definition VCR and to digital recording. It is emphasized that these results are derived not only from the ring-shaped core geometry but also from the isotropic behavior in the magnetic properties of the sputtered Fe-Si-Al alloy films. The experimental results on the isotropic magnetic behavior are summarized. A mass-production process for the laminated alloy film heads is introduced, emphasizing the importance of stacked bar fabrication steps     

Natural history of scoliosis in spastic cerebral palsy

BACKGROUND: Although the frequent occurrence of scoliosis in patients who have spastic cerebral palsy is well known and surgical treatment has often been recommended for these patients, little is known about the natural history of scoliosis in this population. We aimed to clarify the natural history of scoliosis from childhood through to adulthood and provide objective data on proper surgical indications for such patients. METHODS: The participants were 37 institutionalised patients with severe spastic cerebral palsy and scoliosis. All the participants had a series of radiographs taken, starting at a mean age of 7.8 years; they were followed up for an average of 17.3 years. We retrospectively reviewed radiographs and assessed the effect of five factors on progression of scoliosis: sex, degree of spasticity, initial physical capability, pattern of spinal curve, and location of curve. FINDINGS: Scoliosis usually started before the age of 10 years and progressed rapidly during the growth period. In many cases, even after growth had ended, continuous progression was seen. The mean magnitude of the curves at final examination was 55 degrees (Cobb angle). In 11 (85%) of 13 patients who had a spinal curve of more than 40 degrees before age 15 years, the scoliosis progressed to more than 60 degrees by the time of the final examination. Meanwhile, in only three (13%) of 24 patients who had a curve of less than 40 degrees at age 15 years, did the scoliosis progress to more than 60 degrees. Severe scoliosis (> or = 60 degrees) developed predominantly in those who had total body involvement (67%), were bedridden (100%), or had throacolumbar curves (57%). INTERPRETATION: The risk factors for progression of scoliosis in spastic cerebral palsy are: having a spinal curve of 40 degrees before age 15 years; having total body involvement; being bedridden; and having a thoracolumbar curve. Patients with these risk factors might benefit from early surgical intervention to prevent progression to severe scoliosis.     

Implementation and performance evaluation of pass‐through PPTP relay system with authentication at each gateway

The VPN (Virtual Private Network) technique is becoming increasingly popular as a way to protect the contents of messages and to achieve secure communications immune to such activities as eavesdropping. However, although VPN servers are increasingly used on a subnetwork in part of an officewide network, the PPTP system included in the Windows operating systems cannot establish nested VPN links. Moreover, encrypted communication by VPN hides the user of the VPN connection, and consequently the administrators of network systems cannot determine the users of the VPN connection via the firewall, or decide whether a user is legal or not. In order to solve this problem, we developed a multistep PPTP relay system on a firewall. This system solves all the problems of our previously developed PPTP relay system [1]. The new relay system improves security by end‐to‐end encryption of communication and eliminates the prior registration of passwords for the next step. Furthermore, the transport speed is increased and the restriction on the number of relay steps is also eliminated. These features of the multistep PPTP relay system expand its usability. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(2): 40–51, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20183     

Broadband ultrasonic transducers using a LiNbO3 plate with a ferroelectric inversion layer

Some heat treatment of a lithium niobate (LiNbO/sub 3/) plate induces domain inversion, thereby yielding a ferroelectric inversion layer. In such a piezoelectric plate with an inversion layer, even-order thickness-extensional modes, as well as odd-order modes, can be excited piezoelectrically. Therefore, the ultrasonic transducer using such a piezoelectric plate is expected to operate over a wide frequency range. In this paper, it is shown that broadband ultrasonic transducers can be obtained at a certain thickness ratio of inversion layer to plate, and that the transducer characteristics differ depending on whether the inversion layer is on the front side or on the backside. The broadband characteristics are experimentally demonstrated by fabricating transducers with 9 MHz or 75 MHz center frequency using 36/spl deg/ rotated Y-cut LiNbO/sub 3/ plates with a ferroelectric inversion layer.     

Electrical communication between glucose oxidase and electrodes mediated by phenothiazine-labeled poly(ethylene oxide) bonded to lysine residues on the enzyme surface

A series of glucose oxidase (GOx) hybrids (GOx-phe-nothiazine-labeled poly(ethylene oxide) (PT-PEO)) capable of direct electrical communication with electrodes is synthesized by covalently modifying PT-PEO to lysine residues on the enzyme surface. The length of the PEO chain and the number of PT groups are systematically altered. After the PT-PEO modification, all the hybrids maintain more than 50% of enzyme activity relative to that of native GOx, although loss of the activity becomes greater with increasing PEO chain length. The catalytic current, i(cat), is observed at a potential more positive than 0.55 V after the addition of glucose, due to the intramolecular electron transfer (El) from reduced forms of flavin adenine dinucletide (FADH2/FADH) to PT+ that are electrogenerated at the electrode. The i(cat) value increases with the number of PT groups, indicating that most of the modified PT groups act as mediators. The magnitude of the i(cat) increase depends on the PEO chain length and reveals a maximum for PT-PEO with the molecular weight of 3,000. In contrast, the i(cat) is almost constant for GOx-2-(10-phenothiazyl)propionic acid (PT-PA) hybrids with more than two PT groups synthesized by covalently modifying PT-PA to surface lysines, indicating that only a few key PT groups function as mediators. The maximum rate constant (130 s(-1)) for the ET from FADH2/FADH to PT+ is obtained for the GOx hybrid modified with five PT-PEO groups with the molecular weight of 3,000.     

Lipid synthesis and acyl-CoA synthetase in developing rice seeds

Developing rice seeds rapidly accumulated storage lipids between 5 and 12 d after flowering. The contents of palmitic, oleic, and linoleic acids increased throughout seed development, while the alpha-linolenic acid content remained low. The activity of acyl-CoA synthetase varied coincidentally during the period of lipid accumulation, and rice seeds had a sufficient capacity to supply acyl-CoA substrates for TAG synthesis. Acyl-CoA synthetase showed a broad specificity for native FA of rice seeds except for stearic acid, and pi electrons of a delta9-delta11 double bond in the C16-C18 acyl chains were required for its maximal activity.     

Synthesis and characterization of deoxycholyl 2-deoxyglucuronide: A water-soluble affinity labeling reagent

Acyl glucuronides, which are biosynthesized by the action of glucuronosyltransferases to material for detoxification, are water-soluble and chemically active; they produce irreversible protein adducts via both the transacylation mechanism and the imine mechanism. The acyl group at the C-1 position migrates from the anomeric carbon to the C-2 position of the glucuronic acid moiety, producing the aldehyde group at the C-1 position, where the protein easily condenses through a Schiff's base, in the open-chain aldose form. The elimination of the hydroxyl group at the C-2 position therefore may prevent a protein-bound adduct via the imine mechanism. In this paper, we describe the synthesis and characterization of an acyl 2-deoxyglucuronide of deoxycholic acid as a model compound to investigate its possible utility as a water-soluble affinity labeling reagent for lipophilic carboxylic acids. The solubility of deoxycholyl 2-deoxyglucuronide in an aqueous solution was sufficient under physiological conditions, and the desired material reacted with model peptides to produce covalently bound adducts only via the transacylation mechanism.     

In vitro fertilization and polyspermy in the pig: factors affecting fertilization rates and cytoskeletal reorganization of the oocyte

Polyspermy is a common phenomenon in the pig. Extensive information has become available from in vitro studies on not only the quality of oocytes but also the quality of spermatozoa. However, little information is available on the relative penetration rates of fresh and frozen spermatozoa from the same ejaculate from boars of different breeds. The present results, based on a total of 15 boars of three different breeds, revealed that the inter-breed variation in fertilization and polyspermic rates is larger than intra-breed variation. It was also shown that the incidence of polyspermy as well as penetration rate was greatly decreased by freezing and thawing, even if a higher number of sperm was coincubated with cumulus-free oocytes for a longer period compared to fresh sperm of the same ejaculate. This study focuses on the cytoskeletal organization of the oocyte with respect to the status of cumulus investment, and monospermic and polyspermic fertilization. The status of cumulus cells correlated with the density of transzonal cumulus-cell processes and with the maturation rate of oocytes and, to some degrees, the incidence of polyspermy. Polyspermic zygotes formed multiple microtubule domains in association with individual male pronuclei (PN), but in a high degree of polyspermy (more than trispermy), the pronuclear apposition did not proceed. The effect of multiple PN of paternal and maternal origin on the cytoskeletal reorganization is also discussed.     

Amplitude-division three-electron-wave interference for observing pure phase objects having low spatial frequency

A new interferometry is presented for direct visualization of pure phase objects having low spatial frequency, such as electromagnetic microfields. A thin crystal of silicon prepared using argon ion milling is installed at the standard specimen position. This silicon crystal works as an electron beam splitter and forms diffraction spots in the back focal plane. Using the objective aperture, [000], [111] and [111] spots are selected as coherent electron sources to illuminate the specimen located at the area-selecting aperture position. The lattice image of silicon is formed below the area-selecting aperture position by decreasing the electric current of the objective lens. Three defocused images of the specimen are observed in the fluorescent screen by overexciting the first intermediate lens. We have successfully visualized equipotential lines around a latex particle charged by electron beam irradiation. The computer-simulated image was consistent with the experimental image.