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41.
42.
Cover Picture: Direct Catalytic Addition of Alkylnitriles to Aldehydes by Transition‐Metal/NHC Complexes (Chem. Eur. J. 48/2014) 下载免费PDF全文
43.
Shigeyuki Namiki Kenji Takikawa Mako Kamiya Prof. Tetsuo Nagano Prof. Yasuteru Urano Prof. Kenzo Hirose 《Angewandte Chemie (International ed. in English)》2014,53(24):6085-6089
Live imaging of exocytosis dynamics is crucial for a precise spatiotemporal understanding of secretion phenomena, but current approaches have serious limitations. We designed and synthesized small‐molecular fluorescent probes that were chemically optimized for sensing acidic intravesicular pH values, and established that they can be used to sensitively and reliably visualize vesicular dynamics following stimulation. This straightforward technique for the visualization of exocytosis as well as endocytosis/reacidification processes with high spatiotemporal precision is expected to be a powerful tool for investigating dynamic cellular phenomena involving changes in the pH value. 相似文献
44.
Yukiko Kamiya Fuminori Sato Keiji Murayama Atsuji Kodama Susumu Uchiyama Hiroyuki Asanuma 《化学:亚洲杂志》2020,15(8):1266-1271
Serinol nucleic acid (SNA) is a promising candidate for nucleic acid‐based molecular probes and drugs due to its high affinity for RNA. Our previous work revealed that incorporation of 2,6‐diaminpurine (D), which can form three hydrogen bonds with uracil, into SNA increases the melting temperature of SNA‐RNA duplexes. However, D incorporation into short self‐complementary regions of SNA promoted self‐dimerization and hindered hybridization with RNA. Here we synthesized a SNA monomer of 2‐thiouracil (sU), which was expected to inhibit base pairing with D by steric hindrance between sulfur and the amino group. To prepare the SNA containing D and sU in high yield, we customized the protecting groups on D and sU monomers that can be readily deprotected under acidic conditions. Incorporation of D and sU into SNA facilitated stable duplex formation with target RNA by suppressing the self‐hybridization of SNA and increasing the stability of the heteroduplex of SNA and its complementary RNA. Our results have important implications for the development of SNA‐based probes and nucleic acid drugs. 相似文献
45.
Makoto Suzuki Tetsuya Tateishi Masahiko Matsuzawa Masakatsu Saito 《Macromolecular Symposia》1996,109(1):55-66
Amphoteric PVA hydrogels were made from mixed aqueous solutions of poly(acrylic acid), poly(allylamine) hydrochloride and poly(vinyl alcohol) by repetitive freezing and thawing. The hydrogen bond induced gelation produced an elastic and tough microporous hydrogel which generated tension as high as 0.3MPa corresponding to the solvent exchange from water to acetone. In this paper we show the microscopic structure of hydrogels determined by means of cryo-SEM technique and X-ray analysis. 相似文献
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47.
Dimethylaluminiun chloride has been found to cleave THP ethers selectively without any removal of t-butyldimethylsilyl ethers 相似文献
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49.
Tamotsu Kamiya Kuniyuki Goto Isao Shinohara 《Journal of polymer science. Part A, Polymer chemistry》1979,17(2):561-569
The ionene polymers were prepared by the Menshutkin reaction of α,ω-dibromoalkane (n) with triethylenediamine (TDA) or 4,4′-bipyridil (BP). Resistivities (p) and activation energies of conduction (Ea) were measured for the polymeric 7,7,8,8-tetracyanoquinodimethan (TCNQ) salts with these ionenes. The correlation between the chemical structure of the ionenes and the conductivity was discussed. In the TDA,n-TCNQ complex salts and the BP,n-TCNQ simple salts the salts of the ionenes containing even numbers of CH2 groups showed higher conductivities than those of the ionenes containing odd numbers of CH2 groups. The conductivities determined by the narrower interval between the N+ cations of the main chains were measured in the simple salts. In the complex salts the conductivities determined by the larger interval were measured. The conformational change of the matrix ionenes affected the arrangement of the TCNQ molecules. The values of p were 79.7 and 12.5 Ω cm, and the values of Ea were 0.122 and 0.063 eV for TDA,4-TCNQ complex salt and BP,5-TCNQ complex salt, respectively. 相似文献
50.
Kouichi Sugihara Hiroshi Kamiya Mieko Yamaguchi Takahiro Kaneda Soichi Misumi 《Tetrahedron letters》1981,22(17):1619-1622
Two quinones bridged with a polyether chain and the corresponding hydroquinones were synthesized, and their redox reaction and complexations with sodium and potassium ions were observed. 相似文献