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901.
Myung-Ki Cheoun C. Y. Ryu Toshitaka Kajino Motohiko Kusakabe Grant J. Mathews 《Few-Body Systems》2013,54(1-4):495-499
We report the constraints from primordial nucleosynthesis on a possible time-dependent quark mass. The variation may affect binding energies and Q values as well as resonance properties of light elements through the hadron mass variation in the nucleon–nucleon interaction. Updated light-element abundances and uncertainties along with a new detailed analysis of the resonance properties on the crucial 3He(d, p)4He reaction imply a narrower range on the possible quark-mass variations in the early universe. The optimum concordance region reduces to a value consistent with no variation. 相似文献
902.
For an abelian number field K, Sinnott defined the group C S (K) of circular units of K and found the index formula for [E(K):C S (K)], where E(K) is the group of units of K. Let C W (K) be the subgroup of E(K) consisting of the cyclotomic units of $\mathbb{Q} (\zeta_{n} )$ fixed by $\mathrm{Gal}(\mathbb{Q}(\zeta_{n})/K)$ as was suggested by Washington. The aim of this paper is to find the index formula for [E(K):C W (K)] when the conductor of K has two distinct odd prime divisors. To do this, we first exhibit a basis of C W (K), and then describe the group structure of C W (K)/C S (K) by comparing the basis of C W (K) with that of C S (K) given by Dohmae, from which the index formula for [E(K):C W (K)] can be derived. 相似文献
903.
Sang Soo Yu Ki Hak Kim Young Eon Ihm Dojin Kim Hyojin Kim Soon Ku Hong Chang Soo Kim Hyun Ryu Sangjun Oh 《Journal of magnetism and magnetic materials》2006
Si1−xMnx (x?0.22) thin films were grown by using a thermal evaporator, and their magnetic and electrical properties were investigated. The Si1−xMnx semiconductors are amorphous when Mn concentration is 9.0 at% and less. The electrical resistivities of amorphous Si1−xMnx (x?0.09) semiconductor thin films are in the range of 9.86–6.59×10−4 Ω cm at room temperature and decrease with increasing Mn concentration. The amorphous Si1−xMnx (x?0.09) semiconductor thin films are p-type and hole densities are 3.73×1018–1.33×1022 cm−3 at room temperature. Low temperature magnetization characteristics reveal that amorphous Si1−xMnx (x?0.09) semiconductor thin films are paramagnetic. 相似文献
904.
905.
Doi T Fukuyama T Minamino S Husson G Ryu I 《Chemical communications (Cambridge, England)》2006,(17):1875-1877
When primary unsaturated alcohols were treated with a catalytic amount of RuHCl(CO)(PPh3)3 in benzene under reflux, dimerization reactions took place to give alpha-hydroxymethyl ketones as major product. 相似文献
906.
The in vitro selection of RNAs catalyzing the decarboxylative Claisen condensation provides evidence for the synthesis of fatty acids, the building blocks of lipids and membranes, in the "RNA world". 相似文献
907.
Goluch ED Nam JM Georganopoulou DG Chiesl TN Shaikh KA Ryu KS Barron AE Mirkin CA Liu C 《Lab on a chip》2006,6(10):1293-1299
Functionalized nanoparticles hold great promise in realizing highly sensitive and selective biodetection. We report a single disposable chip which is capable of carrying out a multi-step process that employs nanoparticles--a bio-barcode assay (BCA) for single protein marker detection. To illustrate the capability of the system, we tested for the presence of prostate specific antigen (PSA) in buffer solution and goat serum. Detection was accomplished at PSA concentrations as low as 500 aM. This corresponds to only 300 copies of protein analytes using 1 microL total sample volume. We established that the on-chip BCA for PSA detection offers four orders of magnitude higher sensitivity compared to commercially available ELISA-based PSA tests. 相似文献
908.
Choi SK Oh HM Lee SK Jeong DG Ryu SE Son KH Han DC Sung ND Baek NI Kwon BM 《Natural product research》2006,20(4):341-346
Two biflavonoids, ginkgetin (1) and sciadopitysin (2), were isolated from the MeOH extract of the young branches of Taxus cuspidata, which inhibited phosphatase of regenerating liver-3 (PRL-3) with IC50 values of 25.8 and 46.2 microM, respectively. This is the first report on PRL-3 inhibitors, isolated from natural sources. 相似文献
909.
Kang HM Ryong Kim J Jeomg TS Choi SG Ryu YH Taeg Oh G Baek NI Kwon BM 《Natural product research》2006,20(1):37-41
Two cyclic diarylheptanoids, garugamblin-3 (1) and acerogenin L (2), isolated from the MeOH extract of the fruits of Alnus japonica Steud., inhibited human low-density lipoprotein (LDL) oxidation in the thiobarbituric acid-reactive substance assay with IC(50) values of 2.9 and 1.7 microM, respectively, and they also inhibited cell-mediated LDL oxidation more than 5 times more strongly than that of a well-known antioxidant, probucol, at a concentration of 10 microM. Compound (1) had no effect on the anti-atherogenesis in low-density lipoprotein receptor-deficient mice. 相似文献
910.
Sayama K Nomura A Arai T Sugita T Abe R Yanagida M Oi T Iwasaki Y Abe Y Sugihara H 《The journal of physical chemistry. B》2006,110(23):11352-11360
The photoelectrochemical properties of porous BiVO4 thin-film electrodes on conducting glass for H2 production from water under visible light were investigated. BiVO4 films were prepared by the metal-organic decomposition method, and particles were 90-150 nm in diameter. Under visible-light irradiation, H2 and O2 evolved in a stoichiometric ratio (H2/O2 = 2) from an aqueous solution of Na2SO4 with an external bias. The photocurrent increased with addition of methanol. The band structure of BiVO4 was investigated by open-circuit potential, flat-band potential, X-ray photoelectron spectroscopy, and calculations based on density functional theory. The top of the valence-band potential of BiVO4 was shifted negatively compared to the potentials of the conventional oxide semiconductors without Bi. We surmise that hybridization between the O-2p and Bi-6s orbitals might contribute to the negative shift of the BiVO4 valence band. Treatment with an aqueous solution of AgNO3 improved the photocurrent of the BiVO4 electrode significantly. The maximum incident photon-to-current conversion efficiency at 420 nm was 44%. This value was the highest among mixed-oxide semiconductor electrodes under visible light irradiation. AgNO3 treatment also improved the stability of the photocurrent. The Ag+ ion in/on the BiVO4 catalyzed the intrinsic photogeneration of oxygen with the holes. 相似文献