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101.
Motivated by experiments on single-headed kinesin KIF1A, we develop a model of intracellular transport by interacting molecular motors. It captures explicitly not only the effects of adenosine triphosphate hydrolysis, but also the ratchet mechanism which drives individual motors. Our model accounts for the experimentally observed single-molecule properties in the low-density limit and also predicts a phase diagram that shows the influence of hydrolysis and Langmuir kinetics on the collective spatiotemporal organization of the motors. Finally, we provide experimental evidence for the existence of domain walls in our in vitro experiment with fluorescently labeled KIF1A. 相似文献
102.
Tsuboyama A Takiguchi T Okada S Osawa M Hoshino M Ueno K 《Dalton transactions (Cambridge, England : 2003)》2004,(8):1115-1116
The synthesis, structure, and photophysical properties of a new cyclometalated dinuclear iridium complex, (ppy)2Ir(mu-BPB)Ir(ppy)2 [ppy = 2-phenylpyridine, BPB = 1,4-bis(pyridin-2-yl)benzene], have been investigated. 相似文献
103.
Norihiro?SadatoEmail author Hiroki?Yamada Tomohisa?Okada Masaki?Yoshida Takehiro?Hasegawa Ken-Ichi?Matsuki Yoshiharu?Yonekura Harumi?Itoh 《BMC neuroscience》2004,5(1):56
Background
Sign-language comprehension activates the auditory cortex in deaf subjects. It is not known whether this functional plasticity in the temporal cortex is age dependent. We conducted functional magnetic-resonance imaging in six deaf signers who lost their hearing before the age of 2 years, five deaf signers who were >5 years of age at the time of hearing loss and six signers with normal hearing. The task was sentence comprehension in Japanese sign language. 相似文献104.
The molecular-recognition abilities of a water-soluble chitin derivative, chitin-graft-polysarcosine (2) were investigated using chitinase, lysozyme, and wheat germ agglutinin (WGA). The enzymatic degradabilities of 2 were evaluated using chitinase and lysozyme. The molecular weight of those compounds of 2 with a higher affinity toward water decreased rapidly, as compared with partially deacetylated chitin (1). The 1H NMR spectrum of the low-molecular-weight fraction, yielded after lysozymic hydrolysis, indicated that saccharide residues in the chitinous backbone were specifically recognized by the lysozyme, then beta-glycosidic linkages in the backbone were selectively hydrolyzed. Furthermore, the molecular-recognition ability of the chitinous backbone of graft copolymer 2 toward the lectin WGA was elucidated by the enzyme-linked lectin-binding assay (ELLA). It was revealed that the graft copolymer with a lower degree of substitution (DS) value efficiently interacted with WGA. Interestingly, a graft copolymer having longer polysarcosine side chains showed higher recognition ability toward WGA than that having short side chains. 相似文献
105.
Shirokawa S Kamiyama M Nakamura T Okada M Nakazaki A Hosokawa S Kobayashi S 《Journal of the American Chemical Society》2004,126(42):13604-13605
A highly regio- and diastereoselective TiCl4-mediated vinylogous Mukaiyama aldol reaction using the chiral vinylketene silyl N,O-acetal has been developed. The present vinylogous Mukaiyama aldol reaction provides a unique and effective means of controlling remote asymmetric induction. The methyl group at the alpha-position is important in achieving a high level of stereoselectivity. From a synthetic point of view, this methodology can provide a one-step construction of delta-hydroxy-alpha,gamma-dimethyl-alpha,beta-unsaturated carbonyl unit that is seen in many natural polyketide products. 相似文献
106.
Eguchi K Enomoto S Furuno K Goldman J Hanada H Ikeda H Ikeda K Inoue K Ishihara K Itoh W Iwamoto T Kawaguchi T Kawashima T Kinoshita H Kishimoto Y Koga M Koseki Y Maeda T Mitsui T Motoki M Nakajima K Nakajima M Nakajima T Ogawa H Owada K Sakabe T Shimizu I Shirai J Suekane F Suzuki A Tada K Tajima O Takayama T Tamae K Watanabe H Busenitz J Djurcic Z McKinny K Mei DM Piepke A Yakushev E Berger BE Chan YD Decowski MP Dwyer DA Freedman SJ Fu Y Fujikawa BK Heeger KM Lesko KT Luk KB Murayama H 《Physical review letters》2003,90(2):021802
KamLAND has measured the flux of nu;(e)'s from distant nuclear reactors. We find fewer nu;(e) events than expected from standard assumptions about nu;(e) propagation at the 99.95% C.L. In a 162 ton.yr exposure the ratio of the observed inverse beta-decay events to the expected number without nu;(e) disappearance is 0.611+/-0.085(stat)+/-0.041(syst) for nu;(e) energies >3.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the "large mixing angle" region are excluded. 相似文献
107.
Based on total-energy electronic-structure calculations within the density-functional theory, we find that a high spin state is realized for an ultimate dangling bond unit on an otherwise hydrogen-covered Si(111) surface. We further propose a systematic method of constructing nanometer-scale dangling bond networks that exhibit the ferrimagnetic spin ordering. The interplay between the electron-electron interaction and the surface reconstruction is elucidated. 相似文献
108.
Long lines of periodic hole structures were produced on a gold film, a glass slide and polystyrene by laser ablation using interfering femtosecond lasers split by a transmission grating. An optical system comprising a cylindrical lens added to an imaging system with a transmission grating was used to obtain the interference of two beams along a long length, and high laser fluence was used to achieve laser ablation. The separation of each hole was 6.25 m, and the total length of the structure produced reached 6 mm, which is longest periodic structure produced by a shot of femtosecond laser. PACS 42.62.-b; 07.60.Ly; 42.40.Eq 相似文献
109.
Phrutivorapongkul A Lipipun V Ruangrungsi N Kirtikara K Nishikawa K Maruyama S Watanabe T Ishikawa T 《Chemical & pharmaceutical bulletin》2003,51(2):187-190
Four new chalcone derivatives (1, 4, 7, 10) were isolated from the stem bark of Millettia leucantha KURZ (Leguminosae) along with two known ones (2, 6) and five known flavones (3, 5, 8, 9, 11). Structure elucidation and unambiguous assignment of the isolates were achieved with the aid of 1D and 2D NMR extensive studies. Correlation of 10 to 4 was successfully done by reduction with Et(3)SiH/CF(3)CO(2)H. Moderate cytotoxic activity was observed in chalcones (1, 10), whereas dihydrochalcones (4, 6) showed moderate anti-Herpes Simplex Virus (HSV) activity. Interestingly, flavone 8 showed significant anti-inflammatory effects inhibiting both cyclooxygenase (COX)-1 and -2. 相似文献
110.
Atsuko Okada 《Journal of Mathematical Analysis and Applications》2003,281(2):485-500
In this paper, we study the initial-boundary value problem of a semilinear parabolic equation with localized reaction,