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排序方式: 共有346条查询结果,搜索用时 15 毫秒
21.
Spectroscopic and thermodynamic investigations on complexation of naphthalene-appended amino-beta-cyclodextrins 1 and 2 with cyclic alcohols (cyclohexanol and cycloheptanol) and acyclic alcohols (1-pentanol, 2-pentanol, 1-hexanol, and 1-heptanol) have been carried out. Host 1 exhibits a drastic fluorescent enhanced-signal change in the presence of alcohol guests in aqueous solution. [structure: see text] 相似文献
22.
Yamazoe H Uemura T Tanabe T 《Langmuir : the ACS journal of surfaces and colloids》2008,24(16):8402-8404
Fabrication of micropatterned surfaces to organize and control cell adhesion and proliferation is an indispensable technique for cell-based technologies. Although several successful strategies for creating cellular micropatterns on substrates have been demonstrated, a complex multistep process and requirements for special and expensive equipment or materials limit their prevalence as a general experimental tool. To circumvent these problems, we describe here a novel facile fabrication method for a micropatterned surface for cell patterning by utilizing the UV-induced conversion of the cell adhesive property of albumin, which is the most abundant protein in blood plasma. An albumin-coated surface was prepared by cross-linking albumin with ethylene glycol diglycidyl ether and subsequent casting of the cross-linked albumin solution on the cell culture dish. While cells did not attach to the albumin surface prepared in this way, UV exposure renders the surface cell-adhesive. Thus, surface micropatterning was achieved simply by exposing the albumin-coated surface to UV light through a mask with the desired pattern. Mouse fibroblast L929 cells were inoculated on the patterned albumin substrates, and cells attached and spread in a highly selective manner according to the UV-irradiated pattern. Although detailed investigation of the molecular-level mechanism concerning the change in cell adhesiveness of the albumin-coated surface is required, the present results would give a novel facile method for the fabrication of cell micropatterned surfaces. 相似文献
23.
Maity P Wakabayashi T Ichikuni N Tsunoyama H Xie S Yamauchi M Tsukuda T 《Chemical communications (Cambridge, England)》2012,48(49):6085-6087
Organogold clusters Au(54)(C(2)Ph)(26) were selectively synthesized by reacting polymer-stabilized Au clusters (1.2 ± 0.2 nm) with excess phenylacetylene in chloroform. 相似文献
24.
Non-extractable photoinitiators based on thiol-functionalized benzophenones and thioxanthones 总被引:1,自引:0,他引:1
Hironori Matsushima Qin Li Masamitsu Shirai Charles E. Hoyle 《European Polymer Journal》2010,46(6):1278-1287
Non-extractable photoinitiators could be advantageous for use in biological, electronic, and food packaging applications. Therefore, thioxanthone and benzophenone derivatives were synthesized from 1,6-hexane dithiol and chlorinated benzophenone or thioxanthone. The efficiency of thiol-functionalized photoinitiators in combination with amine co-initiators was compared to benzophenone and isopropylthioxanthone with amine co-initiators, and the cleavage of photoinitiator 2,2-dimethoxy-1,2-diphenylethan-1-one in acrylic resins. The reaction kinetics were analyzed using photo-differential scanning calorimetry and real-time FTIR. Coating physical properties were evaluated by pendulum and pencil hardness, steel-wool scratch and mandrel bend tests. The non-extractable photoinitiators had higher absorbance than their benzophenone or isopropylthioxanthone counterparts due to the sulfide substitution on the phenyl ring, and the free thiol groups reacted with the acrylate by either an amine catalyzed Michael addition or a free-radical chain process. The combination of thiol-functionalized photoinitiators with secondary amines provides an efficient photoinitiator system that is locked into the photopolymerized network and cannot be extracted with typical solvents. 相似文献
25.
Munakata R Katakai H Ueki T Kurosaka J Takao K Tadano K 《Journal of the American Chemical Society》2003,125(48):14722-14723
The first total synthesis of (+)-macquarimicin A (1), a novel inhibitor of neutral sphingomyelinase (N-SMase) with antiinflammatory activity, has been accomplished. The present work determined the absolute configuration of (+)-1 and revised the C(2)-C(3) geometry to be Z. The synthesis features a transannular Diels-Alder reaction, which constructed the tetracyclic framework stereoselectively, and a convergent and efficient synthetic pathway, which afforded (+)-macquarimicin A (1) in 27 steps (longest linear sequence) with 9.9% overall yield. 相似文献
26.
Tadashi Kataoka Hironori Kinoshita 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):989-992
Abstract The Chalcogeno-Morita-Baylis-Hillman reaction was achieved by the reactions of 2-(methylchalcogeno)phenyl vinyl ketones with carbonyl compounds or acetals in the presence of BF3· Et2O. This reaction proceeds via the intramolecular Michael addition of the chalcogenide group to an enone moiety followed by the aldol reaction of the resulting chalcogenonio-enolate with an aldehyde. The reactions were worked up with triethylamine or saturated aqueous NaHCO3 to give the α -methylene aldols (the Morita-Baylis-Hillman adducts). 相似文献
27.
28.
S. K. Deb?Nath Hironori Tohmyoh M. A. Salam?Akanda 《Applied Physics A: Materials Science & Processing》2011,103(2):493-496
A testing methodology to determine the elastic-plastic properties of thin metallic wires is reported. A small-scaled bending
test of Pt thin wire and the corresponding finite element analysis are performed. By fitting the load-displacement relationship
obtained by finite element analysis to the experimental one, the elastic, elastic-plastic properties of Pt wire are successfully
determined. 相似文献
29.
Thermoelastic damping is recognized as a significant loss mechanism at room temperature in micro-scale circular plate resonators. In this paper, the governing equations of coupled thermoelastic problems are established for axisymmetric out-of-plane vibration of circular plate. Then the analytical expression for thermoelastic damping is obtained. The effects of environmental temperature, plate dimensions and boundary conditions on the thermoelastic damping are studied. 相似文献