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排序方式: 共有376条查询结果,搜索用时 15 毫秒
101.
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
102.
B. Feigin M. Jimbo T. Miwa E. Mukhin Y. Takeyama 《Communications in Mathematical Physics》2005,257(2):395-423
Quadratic relations are given explicitly in two cases of chiral conformal field theory, and monomial bases of the representation spaces are constructed by using the Fourier components of the intertwiners. The first case is the (2,1) primary fields for the (p,p)-minimal series Mr,s (1rp–1,1sp–1) for the Virasoro algebra where 1<p/p<2. We restrict ourselves to the case p3, for which the (2,1) primary field exists. The second case is the intertwiners corresponding to the two-dimensional representation for the level k integrable highest weight modules V() (0k) for the affine Lie algebra 相似文献
103.
T Sawayama M Tsukamoto T Sasagawa K Nishimura T Deguchi K Takeyama K Hosoki 《Chemical & pharmaceutical bulletin》1990,38(1):110-115
A new series of highly potent angiotensin-converting enzyme (ACE) inhibitors, 1-(N2-substituted L-lysyl-gamma-D-glutamyl)octahydro-1H-indole-2-carboxylic acids, was synthesized; various acyl groups were introduced at the alpha-amino group of the N-terminal P1 Lys. The effect of the N2-acyl groups on in vitro inhibitory activity and oral antihypertensive effect was examined. All of the synthesized N-acyl tripeptides were found to have in vitro inhibitory activity at an approximately nanomolar level, and showed antihypertensive potency in renal hypertensive rats at a dose of 10 mg/kg, when administered orally. Among them, compounds 7e, g and 9f, i, m showed potent and long-lasting antihypertensive effects compared with enalapril (2a). Their structure-activity relationships are also discussed. 相似文献
104.
M Takeyama K Mori F Takayama K Kondo K Kitagawa N Fujii 《Chemical & pharmaceutical bulletin》1990,38(12):3494-3496
A sensitive and specific double-antibody enzyme immunoassay (EIA) for a substance P (SP)-like immunoreactive substance (SP-IS) was developed. For competitive reactions, the SP-antibody was incubated with SP standard (or sample) and beta-D-galactosidase labeled Tyr8-SP (delayed addition). Free and antibody-bound enzyme hapten were separated by using an anti-rabbit immunoglobulin G coated immunoplate. Activity of the enzyme on the plate was fluorometrically determined. The present immunoassay allows detection of 0.4 to 10 fmol/well of SP. Using the present EIA, SP-ISs in human saliva and plasma were determined. The level of SP-IS in human saliva was about 7 pmol/l, which was almost three times higher than that in human plasma. 相似文献
105.
Kyôzô Takeyama 《Zeitschrift für Physik B Condensed Matter》1983,52(3):253-258
A renormalization scheme based directly on a spatial scaling is presented for a parameter which shows the location of the maximum in the “confining square” of iterated maps of an interval into itself. The cause and the properties of band-mergings are made especially clear in the geometrical set-up which allows one to see the symmetry between the forward and the reverse bifurcations (the orbit-splittings and the band-mergings) in an obvious way and yields an economical estimate of Feigenbaum's ratios. The method is applicable to any sequences and to arbitrary maxima of the mapping function. If the maximum is a cusp, a pseudo fixed “point” causes a finite number of pairwise bandmergings which follow the same number of foregoingband-splittings. 相似文献
106.
Intrinsic ionic heats of transport q
o
*
(ion) and ionic heats of transport Q
o
*
(ion) have been evaluated for 53 aqueous ions at infinite dilution at 25°C using the reduction rule proposed by the authors and the limiting laws of Agar, and of Helfand and Kirkwood without electrophoretic terms. q
o
*
(ion) have been found to correlate linearly with the standard ionic entropies of hydration for the 38 ions investigated. The correlation yields three distinctive proportionality constants indicating that the ions may be divided into three distinctive groups. Although the sign of Q
o
*
(ion) is not definite, all values of q
o
*
(ion) are positive. For 17 ions Q
o
*
(ion) are in good agreement with TS
o
*
(ion). Here, S
o
*
(ion) is the absolute standard ionic entropy of transport which can be obtained from potentiometric measurements on cells. The values of S
o
*
(ion) were determined by Agar, and recently by Lin and coworkers. 相似文献
107.
The structure elucidation of FR-900098 () isolated from a microorganism source and the syntheses of FR-900098 and its N-formyl analogue, FR-31564 (), are described. The latter possesses a superior antimicrobial activity. 相似文献
108.
Y. Awaya M. Akiba T. Katou Hidekazu Kumagai Y. Tendow K. Izumo T. Takahashi A. Hashizume M. Okano T. Hamada 《Physics letters. A》1977,61(2):111-113
The K X-rays from the target elements due to N-ion bombardment are measured with a crystal spectrometer. Some aspects owing to high incident energy are discussed. The Kα satellite, Kα hypersatellite and Kβ satellite peak spacings are obtained. 相似文献
109.
110.
Lee HM Olmstead MM Suetsuna T Shimotani H Dragoe N Cross RJ Kitazawa K Balch AL 《Chemical communications (Cambridge, England)》2002,(13):1352-1353
A sample of C60 containing ca. 9% Kr@C60 has been used to form crystalline (0.09Kr@C60/0.91C60).(NiII(OEP)).2C6H6 whose X-ray crystal structure reveals that the Kr atom is centered within the carbon cage and does not produce a detectable change in the size of the fullerene. 相似文献