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排序方式: 共有322条查询结果,搜索用时 31 毫秒
91.
Toshio Morikawa Xuezheng Li Eriko Nishida Seikou Nakamura Kiyofumi Ninomiya Hisashi Matsuda Yoshimi Oda Osamu Muraoka Masayuki Yoshikawa 《Helvetica chimica acta》2010,93(3):573-586
The MeOH extract from the flowers of Bellis perennis was found to show pancreatic‐lipase inhibitory activity (IC50 455 μg/ml). From the extract, seven new triterpene saponins named perennisaponins G ( 1 ; IC50 163 μM ), H ( 2 ; 137 μM ), I ( 3 ; 147 μM ), J ( 4 ; 148 μM ), K ( 5 ; 223 μM ), L ( 6 ; 81.4 μM ), and M ( 7 ; 195 μM ) were isolated as pancreatic lipase inhibitors. The stereostructures of 1 – 7 were elucidated on the basis of chemical and spectroscopic evidence. 相似文献
92.
Using a competitive nitric oxide (NO)-trapping method between Fe–dithiocarbamate (DTC) complexes and liposome-encapsulated
2-[4-trimethylammonio]-4,4,5,5-tetramethyl-imidazoline-1-oxyl 3-oxide (TMAPTIO), NO-trapping rates of Fe–DTC complexes in
the presence of phosphatidylcholine liposomes were quantified for five kinds of Fe–DTC complexes. We investigated how the
DTC ligand structure influences the NO-trapping rates of Fe–DTC complexes. The negatively charged liposomes give a higher
NO-trapping rate of Fe–DTC complexes than do the positively charged ones, suggesting that the presence of a charge on the
liposome surface affects the NO-trapping rate processes of Fe–DTC complexes. In addition, on the basis of the pressure dependence
experiments for the competitive reaction, we evaluated the difference in activation volumes between the NO-trapping reactions
by Fe–DTC complexes and TMA-PTIO, which allowed us to consider possible reaction mechanisms for the NO-trapping processes. 相似文献
93.
Yoshimi Egawa Hikoe Enomoto Ralph J. Faudree Hao Li Ingo Schiermeyer 《Journal of Graph Theory》2003,43(3):188-198
It is shown that if G is a graph of order n with minimum degree δ(G), then for any set of k specified vertices {v1,v2,…,vk} ? V(G), there is a 2‐factor of G with precisely k cycles {C1,C2,…,Ck} such that vi ∈ V(Ci) for (1 ≤ i ≤ k) if or 3k + 1 ≤ n ≤ 4k, or 4k ≤ n ≤ 6k ? 3,δ(G) ≥ 3k ? 1 or n ≥ 6k ? 3, . Examples are described that indicate this result is sharp. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 188–198, 2003 相似文献
94.
Ochiai M Nishi Y Hashimoto S Tsuchimoto Y Chen DW 《The Journal of organic chemistry》2003,68(20):7887-7888
In the presence of triethylamine, (Z)-(2-acetoxy-1-alkenyl)phenyl-lambda(3)-iodanes react with thioureas or thioamides in MeOH to give 2,4-disubstituted thiazoles directly in good yields. The reaction probably involves generation of highly reactive alpha-lambda(3)-iodanyl ketones through ester exchange of the beta-acetoxy group with liberation of methyl acetate, followed by nucleophilic substitutions with thioureas or thioamides. 相似文献
95.
Yoshimi Egawa Ralph J. Faudree Ervin Györi Yoshiyasu Ishigami Richard H. Schelp Hong Wang 《Graphs and Combinatorics》2000,16(1):81-92
Dirac and Ore-type degree conditions are given for a graph to contain vertex disjoint cycles each of which contains a previously
specified edge. One set of conditions is given that imply vertex disjoint cycles of length at most 4, and another set of conditions
are given that imply the existence of cycles that span all of the vertices of the graph (i.e. a 2-factor). The conditions
are shown to be sharp and give positive answers to conjectures of Enomoto in [3] and Wang in [5].
Revised: July 28, 1999 相似文献
96.
K. Yamamoto M. Yoshimi Y. Tawada Y. Okamoto A. Nakajima S. Igari 《Applied Physics A: Materials Science & Processing》1999,69(2):179-185
The performances of thin-film poly-Si solar cells with a thickness of less than 5 μm on a glass substrate have been investigated.
The cell of glass/back reflector/n-i-p type Si/ITO is well characterized by the structure of naturally surface texture and
enhanced absorption with a back reflector (STAR), where the active i-type poly-Si layer was fabricated by plasma chemical
vapor deposition (CVD) at low temperature. The cell with a thickness of 2.0 μm demonstrated an intrinsic efficiency of 10.7%
(aperture 10.1%), an open-circuit voltage of 0.539 V and a short-current density of 25.8 mA/cm2 as independently confirmed by Japan Quality Assurance. No light-induced degradation is observed. The optical and transport
properties of poly-Si cells are summarized.
Received: 1 March 1999 / Accepted: 28 March 1999 / Published online: 7 July 1999 相似文献
97.
Yuichi Michikawa Kentaro Fujimoto Kenji Kinoshita Seiko Kawai Keisuke Sugahara Tomo Suga Yoshimi Otsuka Kazuhiko Fujiwara Mayumi Iwakawa Takashi Imai 《Analytical sciences》2006,22(12):1537-1545
In the present work, a convenient microarray SNP typing system has been developed using a plastic base that covalently immobilizes amino-modified oligonucleotides. Reliable SNP allele discrimination was achieved by using allelic specificity-enhanced enzymatic extension of immobilized oligonucleotide primer, with a locked nucleic acid (LNA) modification at the SNP-discriminating 3'-end nucleotide. Incorporation of multiple biotin-dUTP molecules during primer extension, followed by binding of alkaline phosphatase-conjugated streptavidin, allowed optical detection of the genotyping results through precipitation of colored alkaline phosphatase substrates onto the surface of the plastic base. Notably, rapid primer extension was demonstrated without a preliminary annealing step of double-stranded template DNA, allowing overall processes to be performed within a couple of hours. Simultaneous evaluation of three SNPs in the genes TGFB1, SOD2 and APEX1, previously investigated for association with radiation sensitivity, in 25 individuals has shown perfect assignment with data obtained by another established technique (MassARRAY system). 相似文献
98.
Yoshimi Ikeuchi Maiko Nakagawa Masakazu Yoshikawa Hidekazu Yoshida Shinichi Sakurai 《Journal of polymer science. Part A, Polymer chemistry》2009,47(10):2530-2538
Novel polyamide with chiral environment was obtained from aromatic diamine, 4,4′‐diaminodiphenylmethane (DADPM), and N‐α‐protected L ‐glutamic acid, N‐α‐benzoyl‐L ‐glutamic acid (Benzoyl‐L ‐Glu‐OH). The optical rotation ([α]D ) of the polyamide was determined to be 3.6° (c = 1.00 g/dL in DMF), implying that the optically active polyamide was obtained. The present polyamide gave a durable self‐standing membrane. The membrane selectively incorporated the D ‐isomer of Ac‐Trp from racemic mixture of Ac‐Trp. The adsorption selectivity toward Ac‐D ‐Trp was determined to be 1.95. It showed chiral separation ability by adopting potential difference as a driving force for membrane transport. The permselectivity was dependent on the potential difference, and at the applied potential difference of 3.0 V, the membrane selectively transported Ac‐D ‐Trp and the permselectivity toward Ac‐D ‐Trp was determined to be 1.84, which was close to the adsorption selectivity of 1.95. Contrary to this, the membrane showed opposite permselectivity at the applied potential difference of 2.0 V and the permselectivity toward the L ‐isomer reached 2.48. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2530–2538, 2009 相似文献
99.
Fan J Yudasaka M Kasuya D Azami T Yuge R Imai H Kubo Y Iijima S 《The journal of physical chemistry. B》2005,109(21):10756-10759
We present in this report a new type of particles with micrometer-order sizes, which we called giant graphitic balls (GG balls). The GG balls are produced by CO2 laser ablation of graphite together with single-wall carbon nanohorns. They have graphitic structures whose layers tend to align parallel with the GG-ball surfaces, resulting in polygonal-like arrangements. Comparing the GG-ball structure with that of the previously reported polygonal graphite-particles, the growth mechanism of the GG ball is discussed briefly. 相似文献
100.