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11.
H Koh Y Hashimoto H Takagi K Hirota H Ishihara A Matsuki 《Canadian Metallurgical Quarterly》1993,42(2):217-224
The purpose of the study was to explore the relationship between the exposure of adolescents in the seventh and eighth grades to cigarette advertising and their being smokers. A survey questionnaire given to 602 adolescents assessed their exposure to cigarette advertising and provided measures of their smoking behavior, demographic characteristics, and some psychosocial variables. The results indicated that exposure to cigarette advertising and having friends who smoked were predictive of current smoking status. Adolescents with high exposure to cigarette advertising were significantly more likely to be smokers, according to several measures of smoking behavior, than were those with low exposure to cigarette advertising. The findings extend previous research identifying factors that may play a role in the initiation and maintenance of smoking among adolescents. 相似文献
12.
The channel throughput for a finite number of packet broadcasting users is analyzed for random access protocols, including slotted persistent carrier sense multiple access (CSMA) with and without collision detection and unslotted persistent CSMA with and without collision detection. We consider bothp - and 1-persistent CSMA. Our results can be extended to infinite population cases (by taking the proper limit), where they agree with the known throughput expressions when available. 相似文献
13.
Thirty-four heifers (24 Holstein, 8 Ayrshire, 2 Jersey) and 12 Holstein steer calves were grouped into 23 blocks of 2 animals each according to breed, sex, and body weight. Animals in each block were randomly assigned to control or treated groups. The treated group received an anthelmintic bolus containing morantel tartrate before they were permitted access to pasture. A 2.6 ha pasture was divided in half with a double fence; the resulting two pastures had separate feed and water troughs. Steer calves were slaughtered upon termination of the trial to ascertain gastrointestinal parasite burdens. Two worm-free tracer calves were placed on each pasture every 2 mo and slaughtered after 4 wk of grazing to determine parasite infectivity of pastures. Herbage samples were obtained monthly and analyzed for infective larvae. The trial was conducted for 141 d during the grazing season. Treatment resulted in 90% reduction in infective larvae on pasture, 74% reduction in fecal worm-eggs, 91% reduction in adult worm burdens, and a trend toward reduced worm burdens in tracer calves by 52%. An overall average daily gain of .68 and .88 kg was obtained for control and treated animals. Reproductive data for the heifers remaining in the herd from the trial showed that treatment resulted in 44 less days to first breeding. 相似文献
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Because of its high–temperature chemical stability, SiC ceramic is a promising material for high-temperature device applications such as thermoelectric energy converters. However, the electrical conductivity of SiC ceramic is too low for it to be used as a thermoelectric energy converter at the cold junction. Therefore, we propose a SiC-Si functionally gradient material (FGM) in order to improve the electrical conductivity of the SiC ceramic at the cold junction. An SiC rod was fired in a temperature gradient furnace. One end of the SiC rod was maintained at 2473 K and the other end was maintained at 1973 K for 30 min. After firing, the porous SiC edge fired at 1973 K was dipped into molten Si in order to infiltrate molten Si into the porous SiC. The microstructure of the FGM is classified into three regions: the SiC-Si composite material; the porous SiC ceramic; and the densified SiC ceramic. The electrical conductivity, the Seebeck coefficient and the thermal conductivity for each region of SiC-Si FGM was measured at 300 K; a figure of merit was calculated. The figure of merit of the SiC-Si FGM at the cold junction, at room temperature, was 108 times higher than that of a nongradient SiC ceramic. 相似文献
16.
T Imai M Baba M Nishimura M Kakizaki S Takagi O Yoshie 《Canadian Metallurgical Quarterly》1997,272(23):15036-15042
Thymus and activation-regulated chemokine (TARC) is a recently identified CC chemokine that is expressed constitutively in thymus and transiently in stimulated peripheral blood mononuclear cells. TARC functions as a selective chemoattractant for T cells that express a class of receptors binding TARC with high affinity and specificity. To identify the receptor for TARC, we produced TARC as a fusion protein with secreted alkaline phosphatase (SEAP) and used it for specific binding. By stably transfecting five orphan receptors and five known CC chemokine receptors (CCR1 to -5) into K562 cells, we found that TARC-SEAP bound selectively to cells expressing CCR4. TARC-SEAP also bound to K562 cells stably expressing CCR4 with a high affinity (Kd = 0.5 nM). Only TARC and not five other CC chemokines (MCP-1 (monocyte chemoattractant protein-1), RANTES (regulated upon activation, normal T cells expressed and secreted), MIP-1alpha (macrophage inflammatory protein-1alpha), MIP-1beta, and LARC (liver and activation-regulated chemokine)) competed with TARC-SEAP for binding to CCR4. TARC but not RANTES or MIP-1alpha induced migration and calcium mobilization in 293/EBNA-1 cells stably expressing CCR4. K562 cells stably expressing CCR4 also responded to TARC in a calcium mobilization assay. Northern blot analysis revealed that CCR4 mRNA was expressed strongly in human T cell lines and peripheral blood T cells but not in B cells, natural killer cells, monocytes, or granulocytes. Taken together, TARC is a specific functional ligand for CCR4, and CCR4 is the specific receptor for TARC selectively expressed on T cells. 相似文献
17.
Hiroyuki Miki Takanori Takeno Toshiyuki Takagi Alexei Bozhko Mikhail Shupegin Hideya Onodera Takao Komiyama Takashi Aoyama 《Diamond and Related Materials》2006,15(11-12):1898
Superconductivity in a tungsten-containing carbon-oxide film was reported. The film with 500 nm thickness was deposited onto polycrystalline silicon oxides using chemical vapor deposition and the co-sputtering of a tungsten metal target. The bonding state of the carbon atoms and the macroscopic and microscopic crystal structure of the film were investigated by Raman spectroscopy, X-ray diffraction and transmission electron microscopy measurements. From the experimental results, we determined that this film essentially had an amorphous structure. The temperature dependence on resistivity was measured in the temperature range of 2–300 K. Resistive superconducting transition was observed at 3.8 K. The dc magnetizations were measured in the temperature range of 1.8–6.5 K. The diamagnetism resulting from a superconductive state was observed below 3.75 K, which is consistent with a resistive superconducting transition. It is thought that the finite sized clusters of the different superconductive transition temperatures cooperatively produce a macroscopic superconducting phenomenon. 相似文献
18.
A case of Waldenstr?m's macroglobulinemia (WM) (IgM-kappa type) associated with acute-onset demyelinating peripheral neuropathy is reported. A 49-year-old woman was admitted to our hospital because of general fatigue and recurrent syncope attacks. She was treated with vincristine, cyclophosphamide, epirubicin and prednisolone. By 10th hospital day, her clinical condition improved and serum viscosity was reduced. However, on the 21st hospital day, she suffered from rapidly progressive writing and gait disturbance. Neurological examination showed muscular atrophy and weakness in the distal part of four extremities. Deep tendon reflexes were diminished. There was no sensory deficit. Cerebrospinal fluid was normal. Anti-myelin associated glycoprotein activity of her serum was negative. Both motor and sensory nerve conduction velocities were markedly decreased. Biopsy of sural nerve revealed marked demyelination and onion bulb formation. There was IgM deposition on myelin sheath. Minimal axonal changes excluded the possibility of vincristine neuropathy. Plasmapheresis improved her symptoms, but nerve conduction velocities remained unchanged. Polyneuropathy associated with WM is usually gradual onset and sensory dominant. In this case, associated neuropathy was acute onset, progressive and motor dominant. This type of neuropathy in patients with WM is very rare. 相似文献
19.
This paper reports on a study of the inversion-layer mobility in n-channel Si MOSFETs fabricated on a silicon-on-insulator (SOI) substrate. In order to make clear the influences of the buried-oxide interface on the inversion-layer mobility in ultra-thin film SOI transistors, SOI wafers of different quality at the buried-oxide interface were prepared, and the mobility behaviors were compared quantitatively. The transistors with a relatively thick SOI film exhibited the universal relationship between the effective mobility and the effective normal field, regardless of the buried-oxide interface quality. It was found, however, that Coulomb scattering due to charged centers at the backside interface between SOI films and buried oxides has great influence on the effective mobility in the thin SOI thickness region, depending on the buried-oxide interface quality. This means that Coulomb scattering due to charged centers at the buried-oxide interface can degrade the mobility with decreasing SOI thickness, unless the SOI wafer quality at the buried-oxide interface is controlled carefully 相似文献
20.