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排序方式: 共有348条查询结果,搜索用时 15 毫秒
1.
Hiraki M. Uano K. Minami M. Sato K. Matsuzaki N. Watanabe A. Nishida T. Sasaki K. Seki K. 《Solid-State Circuits, IEEE Journal of》1992,27(11):1568-1574
A BiCMOS logic circuit applicable to sub-2-V digital circuits has been developed. A transiently saturated full-swing BiCMOS (TS-FS-BiCMOS) logic circuit operates twice as fast as CMOS at 1.5-V supply. A newly developed transient-saturation technique, with which bipolar transistors saturate only during switching periods, is the key to sub-2-V operation because a high-speed full-swing operation is achieved to remove the voltage loss due to the base-emitter turn-on voltage. Both small load dependence and small fan-in dependence of gate delay time are attained with this technique. A two-input gate fabricated with 0.3-μm BiCMOS technology verifies the performance advantage of TS-FS-BiCMOS over other BiCMOS circuits and CMOS at sub 2-V supply 相似文献
2.
J. Masamoto K. Matsuzaki T. Iwaisako K. Yoshida K. Kagawa H. Nagahara 《应用聚合物科学杂志》1993,50(8):1317-1329
Conventionally, acetal homopolymer or copolymer is obtained by the polymerization of formaldehyde or trioxane, following the end-capping using acetic anhydride or unzipping of the unstable polymer end fraction. First, Asahi Chemical developed a new process to obtain an end-capped polymer during polymerization of highly purified formaldehyde using acetic anhydride as the chain-transfer agent. Use of highly purified formaldehyde and endcapping during polymerization using acetic anhydride as a chain-transfer agent or an endcapping agent will provide a simple process for manufacturing acetal homopolymer. The polymerization mechanism was confirmed by infrared spectroscopy analysis and proton NMR analysis of the polymer obtained. Second, for the acetal copolymer, purified trioxane was copolymerized with ethylene oxide in the presence of methylal, which gave an endcapped polymer with high thermal stability. Two new intermediates from the initiation reaction of the copolymerization, 1,3,5,7-tetraoxacyclononane (TOCN) and 1,3,5,7,10-pentaoxacyclododecane (POCD), were isolated and a new initiation mechanism was proposed. © 1993 John Wiley & Sons, Inc. 相似文献
3.
Copper amine oxidase contains a covalently bound quinonoid cofactor, 2,4,5-trihydroxyphenylalanyl quinone (TPQ), which is synthesized by post-translational modification of a specific tyrosyl residue occurring in the highly conserved sequence, Asn-Tyr-(Asp/Glu)-Tyr. To elucidate the role(s) of the conserved sequence in the biogenesis of TPQ, each of the corresponding residues at positions 401-404 in the recombinant histamine oxidase from Arthrobacter globiformis has been replaced with other amino acids by site-directed mutagenesis. When Asn-401 was changed to Asp or Gln, the rate of TPQ formation by copper-dependent self-processing was 10(3)- to 10(4)-fold slower than in the wild-type enzyme. When Tyr-402 was replaced by Phe, TPQ was not formed at all, showing that Tyr-402 is essential as the precursor to TPQ. In contrast, Asp-403 could be replaced by Glu without changes in the rate of TPQ formation, whereas its replacement by Asn led to a marked decrease. Furthermore, when Tyr-404 was changed to Phe, TPQ was formed swiftly on incubation with copper ions, but the TPQ enzyme exhibited very low activity with altered substrate specificity. These results collectively indicate that a very rigorous structural motif is required for efficient formation of TPQ and for the catalytic activity in the active site of copper amine oxidases. 相似文献
4.
S Murakami T Igarashi T Yuhiki T Tobe K Mikami S Akimoto J Shimazaki O Matsuzaki 《Canadian Metallurgical Quarterly》1994,85(8):1213-1217
In order to evaluate the significance of repeat transurethral resection (TUR) in differentiating stage A1 prostatic adenocarcinoma from those with stage A2, we performed repeat TUR in 34 patients with an initial diagnosis of stage A1 prostatic adenocarcinoma. It was found that residual adenocarcinoma was present in five cases (14.7%), but the diagnosis was changed from stage A1 to stage A2 in only one case (2.9%). In one patient with final diagnosis of stage A1 carcinoma, bone metastases were detected seven months after the repeat TUR. It was concluded that repeat TUR for stage A1 prostatic adenocarcinoma did not yield clinically significant information. 相似文献
5.
6.
Antibodies reactive with peptide epitopes on the core protein of MUC1 epithelial mucin have been demonstrated in some patients with adenocarcinomas. Because these epitopes can be exposed on MUC1 in the serum of healthy women, we measured concentrations of MUC1-reactive antibodies in the serum of healthy pregnant and non-pregnant women, and in patients with benign and malignant ovarian tumours. Antibodies were measured in an enzyme-linked immunosorbent assay utilising a synthetic peptide corresponding to a 105-amino-acid segment of the MUC1 tandem repeat region (5.25 repeats). MUC1-reactive antibodies were always of an IgM isotype and concentrations were highest in young healthy women and declined progressively with age (P=0.0006) concomitantly with increasing serum MUC1 levels (P=0.003). Regardless of age, antibody levels were lower in cancer patients than in healthy women (P<0.0001), but MUC1 levels were much higher in cancer patients (P<0.0001). Although high antibody levels were associated with greater survival in ovarian cancer (P=0.015), multivariate regression analysis showed that this was not a significant independent prognostic indicator after consideration of the International Federation of Gynaecology and Obstetrics (FIGO) stage, histological type, serum MUC1 levels and age. Serial measurement of MUC1 and MUC1 antibodies during treatment in 18 patients with ovarian cancer and throughout pregnancy in 10 women showed a negative correlation between alterations in MUC1 and MUC1 antibodies. These results show that MUC1-peptide-reactive antibodies are present in the serum of healthy women and women with cancer and that they probably form immune complexes with MUC1, but provide no evidence for an augmentation of the humoral immune response to MUC1 in ovarian cancer 相似文献
7.
T Yamamura H Matsuzaki K Seo M Kimura T Shinagawa 《Canadian Metallurgical Quarterly》1998,28(11):1175-1178
We report herein the case of a 59-year-old woman who developed a local recurrence of rectal cancer which showed extremely rapid growth. The patient had undergone a curative low anterior resection with total mesoexcision, and was discharged on postoperative day 25 after an uneventful recovery. However, 2 months after the operation, she developed bleeding from the rectum during defecation, the quantity of which gradually increased. A colonoscopy performed during the fifth postoperative month revealed a circular tumor at the suture line. The tumor was unresectable because it had firmly invaded not only the sacrum, but also the right ureter. Despite the administration of 5-fluorouracil and leucovorin, the patient died of cancer 18 months after her initial surgery. Considering that local recurrence of rectal cancer does not usually occur within 1 year after surgery, this case is unusual because the local recurrence developed very early and showed extremely rapid growth, occupying the entire lumen of the rectum by the time it was detected by colonoscopy during the fifth postoperative month. 相似文献
8.
T Ohtsuka N Koibuchi S Matsuzaki A Yamakage S Yamazaki 《Canadian Metallurgical Quarterly》1998,139(6):1047-1048
Using in situ hybridization techniques, we examined the expression of ornithine decarboxylase (ODC) mRNA in the skin of five patients with systemic sclerosis (SSc) and five normal controls. Sections treated with an anti-sense probe showed concentrated grains exclusively in the epidermis of SSc patients, but not in that of normal controls. Because our subcloned anti-sense probe specifically hybridizes with ODC mRNA, these findings indicate that the expression of ODC mRNA is elevated in SSc epidermis. Possibly polyamines have an important part to play in the skin changes of SSc. 相似文献
9.
Application of the sputtering technique to (Al2O3)xBi100–x and (AIN)x Bi100–x (x = 0 to 100%) has been found to result in the formation of a duplex material consisting of hexagonal bismuth particles dispersed finely and homogeneously in amorphous AlxOy and AlxNy matrices. The particle size and interparticle distance of the bismuth phase were about 5 to 140nm and 5 to 35 nm. The duplex alloys have high electrical resistivities ranging from 1.82 × 103 to 3.16 × 105 cm combined with a negative temperature-dependent resistivity of 148 to 342% of 273. Furthermore, all the Al-O-Bi and Al-N-Bi alloys have been found to exhibit a positive magnetoresistive change and the maximum value, (H), at 4.2 K and 7.5T reaches 5.85 × 104 cm for (Al-O)65.7Bi34.3 and 1.99 × 105 cm for (Al-N)69.7 Bi30.3. The large magnetoresistivities are probably due to the unique sputtered structure consisting of metallic bismuth particles with a long mean free path of electrons embedded finely and homogeneously in amorphous AlxOy or AlxNy matrix, resulting in the large difference of the relaxation times (different mobilities) of electron carriers. It has thus been demonstrated that the oxide- or nitride-based composite materials exhibiting large magnetoresistivities, which cannot be achieved in metallic composite materials, are obtained by sputtering simultaneously Al2O3 or AIN and bismuth which is immiscible to aluminium. 相似文献
10.
The sputter-quenched Al
x
O
y
alloys containing lead and bismuth elements, which are insoluble to aluminium; have been found to exhibit a remarkably enhanced upper critical field,H
c2, which is higher by about 6 to 66 times than those of pure lead metal and Pb60Bi40 alloy. The sputtered structure consists of amorphous Al
x
O
y
and f c c lead or h c p (lead-bismuth) phases. The lead and phases disperse homogeneously in the amorphous matrix and their particle sizes and interparticle distances are about 10 to 20 nm and 5 to 20 nm, respectively, for lead and particles. The superconducting transition temperature,T
c, upper critical magnetic field,H
c2, at 4.3 K, and residual resistivity at 10 K are 7.74 K, 3.3 T and 2.09 × 105cm, respectively, for (Al-O)92.8 Pb7.2 and 7.45 K, 8.2 T and 1.70 × 106 cm, respectively, for (Al-O)86.2(Pb0.6 Bi0.4)13.8. The remarkable enhancement ofH
c2 is interpreted as being mainly due to a remarkable decrease of the coherence length resulting from a large reduction of the effective mean free path of electrons. Additionally, the fluxoid pinning force under applied field has also been markedly enhanced for the duplex structure films than for sputtered lead film, probably because of the change of the dispersed lead phase into a type-II superconductor and an effective fluxoid pinning action at the interface between Al
x
O
y
and fine lead particles. 相似文献