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21.
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Yu Nagao Akinori Takasu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(19):4207-4218
Click Cu(I)‐catalyzed polymerizations of diynes that contained ester linkages and diazides were performed to produce polyesters (click polyesters) of large molecular weights [(~1.0–7.0 ) × 104], that contained main‐chain 1,4‐disubstitued triazoles in excellent yields. Incorporation of triazole improved the thermal properties and magnified the even‐odd effect of the methylene chain length. We also found that, by changing the positions of the triazole rings, the thermal properties of the polyesters could be controlled. The use of in situ azidation was a safe reaction, as explosive diazides are not used. In addition, the microwave heating was found to accelerate the polymerization rates. This is the first study that has applied click chemistry for the synthesis of a series of polyesters. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4207–4218, 2010 相似文献
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Takenobu Nii Katsuhiro Konno Masaki Matsumoto Kanit Bhukhai Suparerk Borwornpinyo Kazuhiro Sakai Suradej Hongeng Daisuke Sugiyama 《Molecules (Basel, Switzerland)》2021,26(7)
Hematopoietic stem and progenitor cell (HSPC) transplantation is a curative treatment of hematological disorders that has been utilized for several decades. Although umbilical cord blood (UCB) is a promising source of HSPCs, the low dose of HSPCs in these preparations limits their use, prompting need for ex vivo HSPC expansion. To establish a more efficient method to expand UCB HSPCs, we developed the bioactive peptide named SL-13R and cultured UCB HSPCs (CD34+ cells) with SL-13R in animal component-free medium containing a cytokine cocktail. Following 9 days of culture with SL-13R, the numbers of total cells, CD34+, CD38− cells, and hematopoietic stem cell (HSC)-enriched cells were significantly increased relative to control. Transplantation of cells cultured with SL-13R into immunodeficient NOD/Shi-scid/IL-2Rγ knockout mice confirmed that they possess long-term reconstitution and self-renewal ability. AHNAK, ANXA2, and PLEC all interact with SL-13R. Knockdown of these genes in UCB CD34+ cells resulted in reduced numbers of hematopoietic colonies relative to SL-13R-treated and non-knockdown controls. In summary, we have identified a novel bioactive peptide SL-13R promoting expansion of UCB CD34+ cells with long-term reconstitution and self-renewal ability, suggesting its clinical use in the future. 相似文献
25.
Keiji Konno Mitsuru Ueda Paul Youngman John W. Fitch Patrick E. Cassidy 《Journal of polymer science. Part A, Polymer chemistry》1997,35(11):2267-2272
Poly(arylene ether)s ( 3 ), ( 4 ) containing pendant benzoyl groups as precursors for novel polyxanthenes ( 7 ), ( 8 ) were prepared by nucleophilic substitution reaction of 2,5-difluoro-4-benzoylbenzophenone ( 1 ) or 2,5-difluoro-4-(4-dodecylbenzoyl)-4′-dodecylbenzophenone ( 2 ) with hydroquinone derivatives in the presence of potassium carbonate in N,N-dimethylacetamide. The polycondensation proceeded smoothly at 165°C and produced poly(arylene ether)s with inherent viscosities up to 0.80 dL/g. The novel polyxanthenes were synthesized via the reduction of poly(arylene ether)s followed by the Friedel-Crafts cyclization of diol polymers. The structure of the polyxanthenes was characterized by 1H-NMR and IR spectroscopies. Polyxanthene 8 was quite soluble in chloroform and THF. The 10% weight loss temperature of polyxanthene 7 was 510°C in nitrogen and it was 90°C higher than the corresponding poly(arylene ether) 3 . © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2267–2272, 1997 相似文献
26.
Thallada Bhaskar Kazuya Murai Toshiki Matsui Mihai Adrian Brebu Md. Azhar Uddin Akinori Muto Yusaku Sakata Katsuhide Murata 《Journal of Analytical and Applied Pyrolysis》2003,70(2):369-381
The thermal degradation of acrylonitrile-butadiene-styrene copolymer (ABS-Br; 10 g) containing brominated flame retardant (Br: 9.59 wt.%) was carried out at 450 °C using a semi batch operation using two different temperature programs. The heating rate was found to affect the quality of the degradation oil and yield of products (liquid, gas and residue). Data on the effect of the temperature program on the accumulation of liquid products was presented. It was found that the majority of the bromine was concentrated in the carbon residue and while majority of the nitrogen accumulates in the liquid products irrespective of degradation mode. The use of a one step constant heating rate process (I) produced a higher liquid yield (39%), than a two step process (29%). Differences were also noted in the Br and N contained in the liquids produced by the two processes. 相似文献
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Marco Carini Mauro Marongiu Karol Strutyski Akinori Saeki Manuel Melle‐Franco Aurelio Mateo‐Alonso 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(44):15935-15939
Supramolecular polymers show great potential in the development of new materials because of their inherent recyclability and their self‐healing and stimuli‐responsive properties. Supramolecular conductive polymers are generally obtained by the assembly of individual aromatic molecules into columnar arrays that provide an optimal channel for electronic transport. A new approach is reported to prepare supramolecular polymers by hooking together sigmoidal monomers into 1D arrays of π‐stacked anthracene and acridine units, which gives rise to micrometer‐sized fibrils that show pseudoconductivities in line with other conducting materials. This approach paves the way for the design of new supramolecular polymers constituted by acene derivatives with enhanced excitonic and electronic transporting properties. 相似文献
29.
Kento Imanishi Benny Wahyudianto Dr. Tatsuhiro Kojima Dr. Nobuto Yoshinari Prof. Takumi Konno 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(8):1827-1833
Here a unique single-crystal-to-single-crystal (SCSC) transformation of a 116-nuclear AuI72CdII40NaI4 cage-of-cage ( 2 CdNa) is reported, which was created from a trigold(I) metalloligand with d -penicillamine by way of a 9-nuclear AuI6CdII3 cage ( 1 ). Cage-of-cage 2 CdNa is composed of 12 cages of 1 that are linked by 4 Cd2+ and 4 Na+ ions, with its surface being covered by 12 NO3− ions to form a discrete, spherical molecule with a diameter ca. 4.7 nm. In crystal 2 CdNa, the cage-of-cage molecules are packed in a cubic lattice with a huge cell volume of ca. 4.5×105 Å3, so as to have large interstices with diameters of more than 3 nm. Upon soaking crystals 2 CdNa in aqueous Cu(NO3)2, all Cd2+ and Na+ were quickly exchanged by Cu2+ to produce an analogous AuI72CuII44 cage-of-cage ( 2 Cu) in a SCSC manner. Prolonged soaking led to the SCSC transformation to another supramolecular structure ( 2′ Cu) consisting of 152-nuclear AuI72CuII80 cage-of-cages that are alternately H-bonded with the AuI72CuII44 cage-of-cages. 2′ Cu showed the accommodation of MoO42− and the conversion of MoO42− to β-Mo8O264− in the crystal, with retention of single-crystallinity. 相似文献
30.
Hayashi Y Obata N Tamaru M Yamaguchi S Matsuo Y Saeki A Seki S Kureishi Y Saito S Yamaguchi S Shinokubo H 《Organic letters》2012,14(3):866-869
A biphenyl-fused BODIPY was synthesized through a facile oxidative cyclization of peripheral aryl-substituents at the β-position of the BODIPY unit. The extended π-system of the fused BODIPY induces near-infrared (NIR) absorption and strong π-π interactions in the solid state. These features are beneficial for the application of the dye as a functional material. The biphenyl-fused BODIPY dye was demonstrated to exhibit photocurrent conversion ability on the basis of its n-type semiconducting property. 相似文献