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排序方式: 共有1415条查询结果,搜索用时 15 毫秒
91.
Nagatoshi Nishiwaki Tomoya Konishi Shiro Tsukamoto Masahiko Shimoda 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(4):873-876
A palladium catalyst supported on a semiconductor plate underwent the Heck reaction effectively to afford a coupling product.
The catalytic plate was easily recovered from the reaction mixture with tweezers and reused several times without any special
treatment. Comparison of reusability, durability, and treatability of seven kinds of commercially available solid-supported
palladium catalysts and the semiconductor-supported catalyst plate was studied. 相似文献
92.
Kimiyuki Mitsui Makoto Koike Hidehiko Tsukamoto Minoru Yajima 《Precision Engineering》1997,20(2):93-98
Conventional ultrasonic displacement-measuring systems normally employ the pulse-echo technique. Resultant resolution capability, however, typically is not suitable for meeting high-dimensional, in-process measurement standards used in cutting and grinding operations. This paper presents a new ultrasonic sensor for displacement measurement based on astigmatic focus error detection. The measuring principle and basic analysis applied in the design method are described in detail, after which the validity of the principle is demonstrated by the results of experimental evaluations. 相似文献
93.
94.
Md. Mahbubul Alam Shigeru Matsuob Kenbu Teramotob Toshiaki Setoguchib Heuy-Dong Kim 《Journal of Mechanical Science and Technology》2007,21(9):1398-1407
A new passive control technique of cavity-induced pressure oscillations has been investigated numerically for a supersonic
two-dimensional flow over open rectangular cavities at Mac h number 1.83 at the cavity entrance. A subcavity on the front
wall of the cavity covered by a flat plate was evaluated for the effectiveness of controlling cavity-induced acoustic oscillations.
The results showed that sub-cavity is very effective in reducing cavity-induced pressure oscillations. The results also showed
that the resultant amount of attenuation of cavity-induced pressure oscillations was dependent on the length and thickness
of the flat plate, and also on the depth of the sub-cavity used as an oscillation suppressor. 相似文献
95.
H Tsukamoto Y Hamada D Wu RJ Boado WM Pardridge 《Canadian Metallurgical Quarterly》1998,58(1-2):170-177
Visually identified and electrophysiologically characterized sympathetic preganglionic neurons (SPNs) were recorded using the whole-cell voltage clamp technique in slices of neonatal rat spinal cord. Monosynaptic excitatory postsynaptic currents (EPSCs) were evoked by electrical stimulation of the nucleus intercalatus in the presence of strychnine (5 microM) and bicuculline (10 microM). These EPSCs were abolished by the antagonist of AMPA-type glutamate receptors, 6-cyano-7-nitro-quinoxaline-2,3-dione (CNQX; 10 microM). Bath applied noradrenaline (NA; 0.5-50 microM) dose-dependently and reversibly decreased by up to around 60% the amplitude of the EPSC, without affecting the holding current. The EPSC depression by NA was not accompanied by a change in EPSC reversal potential (around +5 mV), nor were inward currents generated by pressure application of glutamate affected by NA application. A comparable degree of EPSC depression was also seen with the alpha2-adrenoceptor agonist clonidine (5 microM), and the alpha2A-agonist oxymetazoline (5 microM), while the alpha1-agonist phenylephrine (100 microM) caused only a 22% depression. The EPSC depression caused by NA (10 microM) was completely antagonized by either the alpha-antagonist phentolamine (10 microM) or the alpha2-antagonist idazoxan (2 microM). Conversely, the beta-adrenoceptor antagonist popranolol (5 microM), and the alpha1-, alpha2B- and alpha2C-antagonist prazosin (2 microM) were without effect. These results indicate that activation of presynaptic alpha2A-adrenoceptors on inputs to SPNs decreases glutamate release. 相似文献
96.
M Ikenaga Y Takano Y Ohtani H Tsukamoto Y Hiki A Kakita I Okayasu 《Canadian Metallurgical Quarterly》1998,48(6):453-459
In order to clarify the cell kinetics of colorectal villous tumors (VT), 21 villous adenomatous areas and 12 carcinomatous areas within villous adenomas were investigated for proliferative activity and apoptosis and compared with a series of 41 tubular tumors (TT), demonstrating elements of intramucosal carcinomas as well as tubular adenomas (so-called carcinoma in tubular adenoma). Proliferation was estimated in terms of Ki-67 labeling indices and mitotic indices, and apoptosis was assessed by DNA nick-end labeling to give apoptotic indices. Apoptotic indices of villous adenomatous and carcinomatous regions were significantly lower than the values for their tubular counterparts. Ki-67 labeling indices were also significantly lower for adenoma components. Apoptotic indices, Ki-67 labeling indices and mitotic indices increased with atypia raised in tubular adenoma components. Correlations of mitotic indices with apoptotic indices, Ki-67 labeling indices with apoptotic indices and mitotic indices with Ki-67 labeling indices were found for each villous tumor group and tubular tumor group, and the apoptosis and proliferation ratios for villous tumors were relatively low, suggesting a tendency for greater growth due to less cell deletion. Although this is only one of the biological features of villous tumor groups, it might play a major role in generation of malignancy. 相似文献
97.
H Sawada H Morimoto A Wake Y Yamasaki Y Izumi M Kuroiwa S Osabe Y Imamura K Egami A Tsukamoto I Sanada T Kiyokawa F Kawano 《Canadian Metallurgical Quarterly》1998,39(11):1085-1091
Thirty patients (median age of 32 years; range, 6-61) with hematologic disorders received unmanipulated peripheral blood stem cell transplants from HLA-matched or one-antigen-mismatched related donors following myeloablative therapy for acute lymphoblastic leukemia (7), acute myelogenous leukemia (6), chronic myelogenous leukemia (8), myelodysplastic syndrome (3), or other disorders (6). Granulocyte colony stimulating factor (G-CSF) mobilized peripheral blood stem cells were collected from donors in 1 to 3 aphereses. The apheresis products contained mean counts of 11.3 x 10(8) (range, 3.8-17.2) nucleated cells/kg and 6.7 x 10(6) (range, 1.3-16.7) CD34+ cells/kg. Graft-versus-host-disease (GVHD) prophylaxis consisted of cyclosporin A plus methotrexate, or FK506 plus methotrexate. All patients received G-CSF following their transplant. Although 1 patient died of pneumonia 6 days after transplantation, the others demonstrated rapid engraftment. Median days to recovery to 500/microliter neutrophils and 20,000/microliter platelets were 13 (range, 8-21) and 14 (range, 1-23) days, respectively. The incidence of acute GVHD grade II-IV was 33%; chronic GVHD developed in 57% of the assessable patients. There were no episodes of graft failure or rejection. Nineteen patients (63%) were alive and in complete remission from 147 to 839 days following their transplant (median follow-up of 560 days). Further follow-up study will be required to assess the incidence of chronic GVHD and graft-versus-leukemia (GVL) effects. 相似文献
98.
K Ohara M Nagai K Tani T Tsukamoto Y Suzuki K Ohara 《Canadian Metallurgical Quarterly》1998,9(7):1291-1294
Alpha 2 adrenergic receptors are thought to play a crucial role in the etiology or treatment of mood disorders. Polymorphism(s) in the promoter region of the alpha 2 receptor may affect the gene expression and be associated with mood disorders. We studied the previously reported polymorphisms of the alpha 2A receptor gene at position-1291 in 114 healthy controls and 103 mood disorder patients. There was statistically no difference between controls and patients in either the genotype or the allele frequency. There was statistically no difference between the genotype and the clinical characteristics. Our results suggest there is no association between this polymorphism in the promoter region of the alpha 2A receptor gene and mood disorders. 相似文献
99.
K Ito T Fujita H Uchisako N Tanaka M Matsui K Tsukamoto T Matsumoto T Nakanishi 《Canadian Metallurgical Quarterly》1994,163(4):873-879
MR imaging of the female pelvis with a local coil (multiple phased array coils) has been reported. With this method, the signal-to-noise ratio (S/N) is improved so that high-resolution images can be obtained. Dynamic contrast-enhanced MR imaging has been reported to be useful in diagnosing uterine neoplasms. However, dynamic MR imaging is done in only limited imaging planes. When multisection dynamic MR imaging with fast gradient-echo sequences is combined with the use of a local coil, high-resolution images can be obtained throughout the entire uterus during a single breath-hold. This pictorial essay illustrates the appearance of the normal uterus and malignant uterine neoplasms on high-resolution multisection dynamic MR images obtained with a Helmholtz-type surface coil. 相似文献
100.
WI Horne B Tandler MA Dubick O Niemel? GM Brittenham H Tsukamoto 《Canadian Metallurgical Quarterly》1997,64(2):90-102
Reproduction of pancreatic iron overload in an animal model has been difficult to achieve primarily because of the first-pass extraction of iron by the liver. We hypothesized that portacaval shunting would avoid this hepatic phenomenon and increase pancreatic iron deposition. An end-to-side portacaval shunt was surgically created in male Sprague-Dawley rats, and they were subsequently fed a carbonyl iron-supplemented diet for 17 weeks. This resulted in marked iron accumulation in the pancreas (1621 +/- 188 micrograms/g) compared to minimal deposition in sham-operated rats fed the same diet (138 +/- 53 micrograms/g). Iron deposition in the acinar and centroacinar cells was confirmed histologically by Gomori staining, as well as by ultrastructural examination. Iron overloading was associated with enhanced oxidative stress evidenced by a twofold increase in the levels of glutathione disulfide and thiobarbituric acid-reactive substances. Also, adducts of proteins with malondialdehyde and 4-hydroxynonenal were demonstrated in acinar and ductal cells. Other apparent consequences of iron overload were a 50% reduction in pancreatic amylase content and a decrease in pancreatic protein concentration. These hypotrophic changes were associated with a reduced mass of zymogen granules in the acinar cells noted histologically. Our results show that a combination of portacaval shunting and carbonyl iron feeding achieve pancreatic iron overload and support the role of oxidative stress in the pathogenesis of iron-induced damage in the pancreas. 相似文献