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排序方式: 共有268条查询结果,搜索用时 0 毫秒
1.
Tomonari Tanaka Ayane Matsuura Yuji Aso Hitomi Ohara 《Journal of Applied Glycoscience》2020,67(4):119
Glycopolymers have attracted increased attention as functional polymeric materials, and simple methods for synthesizing glycopolymers remain needed. This paper reports the aqueous one-pot and chemoenzymatic synthesis of four types of glycopolymers via two reactions: the β-galactosidase-catalyzed glycomonomer synthesis using 4,6-dimetoxy triazinyl β-D-galactopyranoside and hydroxy group-containing (meth)acrylamide and (meth)acrylate derivatives as the activated glycosyl donor substrate and as the glycomonomer precursors, respectively, followed by radical copolymerization of the resulting glycomonomer and excess glycomonomer precursor without isolating the glycomonomers. The resulting glycopolymers bearing galactose moieties exhibited specific and strong interactions with the lectin peanut agglutinin as glycoclusters. 相似文献
2.
Yoshio Yamashita Hideyuki Jinbo Ryuji Kawazu Takateru Asano Hiroshi Umehara 《Polymer Engineering and Science》1991,31(12):855-859
LMR-UV (“low molecular weight resist for uv lithography”), a naphthoquinone-diazide sulfonic acid ester of a novolak resin, is a negative working resist. The mechanism of insolubilization of LMR-UV is based on the facts that the naphthoquinone-diazide moiety is decomposed to indenecarboxylic acid (polar compound) by photolysis upon UV irradiation and that the irradiated resist film insolubilizes in a non-polar developer. LMR-UV reliably forms 0.6 μm lines and spaces over a reflective substrate with steps by using a g-line stepper having a 0.35 NA lens. 0.6 μm-wide aluminum patterns over topography are obtained by use of g-line exposure and reactive ion etching. By use of an i-line aligner (NA = 0.42), LMR-UV resolves 0.25 μm space patterns with overhang profiles. The profiles are due to the large absorption coefficient of 3.8 μm?1. 0.3 μm wide aluminum patterns are formed by i-line exposure and lift-off metallization. 相似文献
3.
SS Tseng PL Weaver Y Liu M Hitomi AM Tartakoff TH Chang 《Canadian Metallurgical Quarterly》1998,17(9):2651-2662
The DBP5 gene encodes a putative RNA helicase of unknown function in the yeast Saccharomyces cerevisiae. It is shown here that Dbp5p is an ATP-dependent RNA helicase required for polyadenylated [poly(A)+] RNA export. Surprisingly, Dbp5p is present predominantly, if not exclusively, in the cytoplasm, and is highly enriched around the nuclear envelope. This observation raises the possibility that Dbp5p may play a role in unloading or remodeling messenger RNA particles (mRNPs) upon arrival in the cytoplasm and in coupling mRNP export and translation. The functions of Dbp5p are likely to be conserved, since its potential homologues can be found in a variety of eukaryotic cells. 相似文献
4.
K Yoshida M Yoshimoto K Sasaki T Ohnishi T Ushiki J Hitomi S Yamamoto M Sigeno 《Canadian Metallurgical Quarterly》1998,74(4):1654-1657
A new stable substrate applicable to the observation of DNA molecules by atomic force microscopy (AFM) was fabricated from a ultrasmooth sapphire (alpha-Al2O3 single crystal) plate. The atomically ultrasmooth sapphire as obtained by high-temperature annealing has hydrophobic surfaces and could not be used for the AFM observation of DNA. However, sapphire treated with Na3PO4 aqueous solution exhibited a hydrophilic character while maintaining a smooth surface structure. The surface of the wet-treated sapphire was found by x-ray photoelectron spectroscopy and AFM to be approximately 0.3 nm. The hydrophilic surface character of the ultrasmooth sapphire plate made it easy for DNA molecules to adhere to the plate. Circular molecules of the plasmid DNA could be imaged by AFM on the hydrophilic ultrasmooth sapphire plate. 相似文献
5.
Hitomi Natomi Toshihito Saitoh Kentaro Sugano Masao Iwamori Masahisa Fukayama Yoshitaka Nagai 《Lipids》1993,28(8):737-742
The composition of the glycosphingolipids of the human gastrointestinal tract was studied. The major neutral glycosphingolipids
were ceramide monohexosides (e.g., GalCer, GlcCer), LacCer, Gb3Cer, Gb4Cer and more polar ones with more than four sugars, whereas neither Gg3Cer nor Gg4Cer were present. The acidic glycosphingolipids consisted of sulfatides and gangliosides such as GM3, GM1, GD3 and GD1a. Also a large amount of sulfatides was found in the gastric mucosa and duodenum. The concentrations of sulfatides in the
fundic mucosa, antral mucosa and duodenum amounted to 416.0, 933.8 and 682.9 nmol/g of dry weight, respectively, exceeding
those in the gastric mucosa and kidney of other mammals. The major molecular species of the sulfatides were identified as
I3SO3-GalCer with hydroxylated longer-chain fatty acids based on the analyses by gas-liquid chromatography and negative ion fast-atom
bombardment mass spectrometry. In contrast, gangliosides in these regions showed a tendency to be lower than sulfatides, and
the molar ratios of sulfatides to gangliosides were about 2.0, whereas those in other parts were less than 0.5. A high content
of sulfatides in the gastric and duodenal mucosa, where mucosa is easily insulted by acid, pepsin and bile salts, may be closely
related to their roles in mucosal protection.
The nomenclature used for gangliosides and other glycosphingolipids follows the system of Svennerholm (Ref. 1) and the recommendation
of the IUPAC-IUB Commission (Ref. 2), respectively. 相似文献
6.
The liver lipogenic enzymes are compared among rats, chickens, frogs and fish. Although the apparent Km values of glucose-6-phosphate
dehydrogenase for glucose-6-phosphate are not much different among all the species, those of malic enzyme for malate are much
higher in chickens and fish than in rats and frogs. Glucose-6-phosphate dehydrogenase showed very high activities compared
with malic enzyme in fish liver, and malic enzyme showed high activities in chicken liver. Although the apparent Km values
of acetyl-CoA carboxylase and fatty acid synthetase for substrates are in the same range among all the animals, the activity
of acetyl-CoA carboxylase seems to be extremely low in fish and frog livers, and that of fatty acid synthetase is low in frog
livers only. In addition, the apparent Km values of α-glycerophosphate acyltransferase of fish liver are very high, and the
enzyme activity appears to be extremely low compared to the others. Therefore, the enzymes at the first steps of both fatty
acid and glycerolipid syntheses of poikilothermos animals appear to be very low. On the other hand, the Ouchterlony double-diffusion
patterns showed that the lipogenic enzymes of chickens, frogs and fish are immunologically different from those of rats, with
the exception of acetyl-CoA carboxylase in chickens. Therefore, it is suggested that the fatty acid and glycerolipid forming
systems of poikilothermos animals are quite different from those of homoiothermos and the lipogenesis is very low in poikilothermos. 相似文献
7.
High oleic acid oil suppresses lung tumorigenesis in mice through the modulation of extracellular signal-regulated kinase cascade 总被引:2,自引:0,他引:2
Yamaki T Yano T Satoh H Endo T Matsuyama C Kumagai H Miyahara M Sakurai H Pokorny J Shin SJ Hagiwara K 《Lipids》2002,37(8):783-788
This study was undertaken to estimate the effect of dietary high oleic acid oil (OA) on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone
(NNK)-induced lung tumorigenesis in mice. Diet containing 10% oil was fed to mice through experimental periods. On day 30
after NNK injection (100 mg/kg body weight, i.p.), the treatment increased the level of prostaglandin E2 (PGE2) as well as proliferating cell nuclear antigen, a marker of cell proliferation in a high linoleic acid oil (LA)-fed group
but not in an OA-fed group. The NNK treatment also induced the activation of an extracellular signal-regulated kinase (Erk)
cascade (Erk, Mek and Raf-1) in an LA-fed group. On the other hand, OA feeding abolished the NNK-induced activation of the
Erk cascade. In conjugation with these events, OA feeding reduced lung tumor incidence and tumor multiplicity (percentage
of mice with tumors) in mice compared with LA feeding at the 20th experimental week. These results suggest that OA suppresses
lung tumorigenesis and that this suppression is correlated with the inhibition of PGE2 production and inactivation of the Erk cascade. 相似文献
8.
Shinya Yamamura Akira Nagata Masato Tsuru Hitomi Tamura 《Simulation Modelling Practice and Theory》2011,19(1):30-46
We have proposed the concept of the virtual segment (VS), in which a global communication service is provided by combining a store–carry–forward scheme using vehicles with broadband wireless/wired network infrastructures along roads connected to the Internet. The VS can be a practical framework for non-real-time, asynchronous message transfer (especially for large messages) in a cost-effective manner. In this study, a critical implementation design issue, the message forward scheduling, in the VS approach is discussed and investigated through computer simulation by our developed VS simulator that has reflected the results of the field experiment for realistic performance evaluation. 相似文献
9.
10.
MAGIC抛光方法及其研究进展 总被引:1,自引:0,他引:1
MAGIC(MAGnetic Intelligent Compounds)是由包含磁性颗粒和磨粒的磁性流体固化形成的新型抛光材料。MAGIC中磁性颗粒形成的特殊排列可使磨粒均匀分布,因而MAGIC抛光可高效地获得小粗糙度的表面;另外,MAGIC可浇铸成形,故可用于复杂型面及狭小内表面的机械化抛光。简要介绍了MAGIC磨石的组成、制作方法、抛光效果以及目前的研究进展情况。 相似文献