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81.
Dithioacetal monoxides were synthesized from aldehydes and cyclohexanone, and reaction of the dithioacetal monoxides with Grignard reagents was investigated. The dithioacetal monoxide synthesized from alkylaldehyde and 4-chlorobenzenethiol reacted with i-PrMgCl to afford the desired alpha-thiomagnesium in high yield. The generated alpha-thiomagnesium was found to be stable at room temperature and to be useful in organic synthesis. In contrast to this, the dithioacetal monoxides derived from benzaldehyde and cyclohexanone did not give satisfactory results. 相似文献
82.
83.
Preparative two-dimensional gel electrophoresis with agarose gels in the first dimension for high molecular mass proteins 总被引:5,自引:0,他引:5
A two-dimensional gel electrophoresis (2-DE) method that uses an agarose isoelectric focusing (IEF) gel in the first dimension (agarose 2-DE) was compared with an immobilized pH gradient 2-DE method (IPG-Dalt). The former method was shown to produce significant improvements in the 2-D electrophoretic separation of high molecular mass proteins larger than 150 kDa, up to 500 kDa, and to have a higher loading capacity, as much as 1.5 mg proteins in total for micropreparative runs. The extraction medium found best in this study for agarose 2-DE of mammal tissues was 6 M urea, 1 M thiourea, 0.5% 2-mercaptoethanol, protease inhibitor cocktail (Complete Mini EDTA-free), 1% Triton X-100 and 3% 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Trichloroacetic acid (TCA) treatment of the agarose gel after IEF is to be carefully weighed beforehand, because some high molecular mass proteins were less likely to enter the second-dimensional polyacrylamide gel after TCA fixation, and proteins such as mouse skeletal muscle actin gave pseudospots in the agarose 2-DE patterns without TCA fixation. As a good compromise we suggest fixation of proteins in the agarose gel with TCA for one hour or less. The first-dimensional agarose IEF gel containing Pharmalyte as a carrier ampholyte was 180 mm in length and 2.5-4.8 mm in diameter. The gel diameter was shown to determine the loading capacity of the agarose 2-DE, and 1.5 mg liver proteins in total were successfully separated by the use of a 4.8 mm diameter agarose gel. 相似文献
84.
Synthesis and Characterization of Aminoporphyrin‐End‐Functionalized Poly(N‐isopropylacrylamide) with Photodynamic and Thermoresponsive Effects 下载免费PDF全文
Yang Yang Yanhui Li Nannan Qiu Guihua Cui Prof. Toshifumi Satoh Prof. Qian Duan 《化学:亚洲杂志》2014,9(5):1379-1387
The novel aminoporphyrin‐end‐functionalized poly(N‐isopropylacrylamide) (PNIPAM) polymer H2N‐TPP‐PNIPAM (TPP=5,10,15,20‐tetraphenyl‐21H,23H‐porphyrin) behaves as a multifunctional platform that displays a photodynamic effect, thermosensitivity, and fluorescence properties. The polymer was designed by using an asymmetrical aminoporphyrin (i.e., H2N‐TPP‐Cl) as the initiator for the atom‐transfer radical polymerization of N‐isopropylacrylamide (NIPAM). The polydispersity index (PDI) obtained by gel‐permeation chromatography indicated that the molecular‐weight distribution was narrow (1.09<PDI<1.27). The lower critical solution temperatures of H2N‐TPP‐PNIPAM showed a decreasing trend as the molecular weight was increased as a result of the incorporation of the porphyrin group at the end of the chain. The fluorescence spectra revealed the luminescent properties of the materials. The results of confocal laser scanning microscopy showed that the polymer could enter the cytoplasm through endocytosis. In addition, the multifunctional platform exhibited low toxicity against normal cells (L929) and cancer cells (Hela) and enhanced photodynamic activity towards HeLa cells, without significant necrocytosis towards L929 cells; as a result this material may be useful in the future for practical photodynamic therapy. 相似文献
85.
86.
We have analyzed the transfer efficiency of ballistic electron emission microscopy (BEEM), taking the finite spot size of the emitted electron beam from scanning probes into account. Three-dimensional diffraction from an aperture at a surface-metal/air interface is introduced to model an effect caused by the finiteness of spot size. As a general trend, the diffraction decreases BEEM transfer efficiency. The diffraction effect increases as the spot size decreases and the air-gap distance increases. In a Au/GaAs sample, BEEM transfer efficiency markedly deteriorates down to 6% of the value derived from a conventional planar tunneling theory when a spot size of 0.2 nm, an air-gap distance of 0.6 nm, and an electron energy of 0.2 eV, measured from the bottom of the GaAs conduction band, are assumed. BEEM transfer efficiency is markedly dependent on the spot size of the emitted hot electron. This result indicates that the BEEM current depends on the spatial resolution of the scanning probe, that is, the condition of the tip apex. 相似文献
87.
88.
Tadashi Miyasaka Hiromichi Tanaka Kazue Satoh Mie Imahashi Kentaro Yamaguchi Yoichi Iitaka 《Journal of heterocyclic chemistry》1987,24(3):873-875
A highly efficient intramolecular nitrene insertion was observed upon irradiation of 6-azidouridine derivatives. The N6,2′-cyclo structure of the product was determined unequivocally by X-ray crystallography. 相似文献
89.
M. Sugawara E. Tamura Y. Satoh Y. Komatsu M. Tago H. Beer 《Heat and Mass Transfer》2007,43(10):1009-1018
Visual observations reveal a complicated flow in the liquid melt and a melting front configuration resulting from horizontal
ice plate melting from above into a 20 wt% calcium chloride aqueous solution. The initial temperature of the ice plate and
the mixture are both −5°C. Small scale “mountain and valley” structures (∼1 mm) appear on the flat melting front just after
melting begins, which have been called “sharkskin”. Innumerable upward and downward flows appear near the sharkskin and are controlled by its “mountain and valley” structure. These typical flows will considerably promote the melting of the
ice plate to be 30% larger as compared to the numerically predicted results assuming a flat melting front (i.e., without the
sharkskin), and also by three times larger compared with the results for melting from below. 相似文献
90.
Hitoshi MomochiTakafumi Noguchi Toshifumi MiyagawaNaoki Ogawa Makoto TadokoroTsuyoshi Satoh 《Tetrahedron letters》2011,52(23):3016-3019
The reaction of lithium α-sulfinyl carbanion of enantiopure dichloromethyl p-tolyl sulfoxide with α,β-unsaturated carbonyl compounds gave optically active 1-chlorocyclopropyl p-tolyl sulfoxides having a carbonyl group with high asymmetric induction from the sulfur chiral center. Reduction of the carbonyl group followed by treatment with Grignard reagent, the 1-chlorocyclopropyl p-tolyl sulfoxides resulted in the formation of enantiopure allenic alcohols via the Doering-LaFlamme-type rearrangement of enantiopure cyclopropylmagnesium carbenoid intermediates. This is the first example for the asymmetric synthesis of allenes by the Doering-LaFlamme allene synthesis. 相似文献