2-fluoroabscisic acid analogues: their synthesis and biological activities     

Kim BT  Min YK  Asami T  Park NK  Kwon OY  Cho KY  Yoshida S 《Journal of agricultural and food chemistry》1999,47(1):313-317

Fluorine was introduced into the 2-position of the side chain of abscisic acid (ABA) analogues by Wittig reaction of alpha-ionone derivatives with ethyl triethylphosphono-2-fluoroacetate. The effects of the fluorinated analogues were evaluated on inhibition of cress seed germination and inhibition of gibberellin-inducible alpha-amylase induction in embryoless barley half-seeds. (2E, 4E)-2-Fluoro-5-(1'-hydroxy-2',6', 6'-trimethyl-2'-cyclohexen-1'-yl)-3-methyl-2,4-pentadienoic acid (5b) showed potent inhibitory activity at the same level as ABA in the cress seed germination test, and 5b also inhibited gibberellin-inducible alpha-amylase induction at 4 x 10(-)(6), 3 times the concentration of ABA (1 x 10(-)(6)) for 50% inhibition of alpha-amylase production. 5b also showed dehydrin induction activity. These results indicate that fluorinated ABA analogues mimic ABA action and can be a lead for a plant growth regulator which regulates plant growth or protects plants from environmental stresses.  相似文献   

Displacement above the hypocenter of the 2011 Tohoku-Oki earthquake   总被引：3，自引：0，他引：3  

Sato M  Ishikawa T  Ujihara N  Yoshida S  Fujita M  Mochizuki M  Asada A 《Science (New York, N.Y.)》2011,332(6036):1395

The moment magnitude (M(w)) = 9.0 2011 Tohoku-Oki mega-thrust earthquake occurred off the coast of northeastern Japan. Combining Global Positioning System (GPS) and acoustic data, we detected very large sea-floor movements associated with this event directly above the focal region. An area with more than 20 meters of horizontal displacement, that is, four times larger than those detected on land, stretches several tens of kilometers long along the trench; the largest amount reaches about 24 meters toward east-southeast just above the hypocenter. Furthermore, nearly 3 meters of vertical uplift occurred, contrary to observed terrestrial subsidence.  相似文献   

A network of superconducting gravimeters detects submicrogal coseismic gravity changes   总被引：8，自引：0，他引：8  

Imanishi Y  Sato T  Higashi T  Sun W  Okubo S 《Science (New York, N.Y.)》2004,306(5695):476-478

With high-resolution continuous gravity recordings from a regional network of superconducting gravimeters, we have detected permanent changes in gravity acceleration associated with a recent large earthquake. Detected changes in gravity acceleration are smaller than 10(-8) meters seconds(-2) (1 micro-Galileo, about 10(-9) times the surface gravity acceleration) and agree with theoretical values calculated from a dislocation model. Superconducting gravimetry can contribute to the studies of secular gravity changes associated with tectonic processes.  相似文献   

Athens variant of glucose-6-phosphate dehydrogenase     

Stamatoyannopoulos G  Yoshida A  Bacopoulos C  Motulksy AG 《Science (New York, N.Y.)》1967,157(3790):831-833

A variant of glucose-6-phosphate dehydrogenase (G6PD), characterized by slower than normal electrophoretic migration and associated with mild deficiency of G6PD in the red cells, was detected in two unrelated Greek males. Electrophoretic, chromatographic, and enzymologic study indicated that the new mutant is structurally different from normal G6PD (B+) and from the Mediterranean variant associated with red-cell enzyme deficiency (B-). Convincing electrophoretic separation of the new variant from the normal B+ and the Mediterranean B- enzymes was achieved only by detailed electrophoretic study in different buffer systems and conditions.  相似文献   

Axle-less F1-ATPase rotates in the correct direction     

Furuike S  Hossain MD  Maki Y  Adachi K  Suzuki T  Kohori A  Itoh H  Yoshida M  Kinosita K 《Science (New York, N.Y.)》2008,319(5865):955-958

F1-adenosine triphosphatase (ATPase) is an ATP-driven rotary molecular motor in which the central gamma subunit rotates inside a cylinder made of three alpha and three beta subunits alternately arranged. The rotor shaft, an antiparallel alpha-helical coiled coil of the amino and carboxyl termini of the gamma subunit, deeply penetrates the central cavity of the stator cylinder. We truncated the shaft step by step until the remaining rotor head would be outside the cavity and simply sat on the concave entrance of the stator orifice. All truncation mutants rotated in the correct direction, implying torque generation, although the average rotary speeds were low and short mutants exhibited moments of irregular motion. Neither a fixed pivot nor a rigid axle was needed for rotation of F1-ATPase.  相似文献   

Void structure in colloidal dispersions     

Ito K  Yoshida H  Ise N 《Science (New York, N.Y.)》1994,263(5143):66-68

The time evolution of void structures in highly purified polymer latex dispersions was studied with a confocal laser scanning microscope. In such dispersions, which were initially homogeneous, the voids grew with time when the dispersions were kept standing and formed more quickly in the internal material than in material close to the glass-dispersion interface. Void formation is thus not an artifact arising from the presence of the interface. A similar structural inhomogeneity, in apparently homogeneous systems, is discussed for simple ionic solutions, ionic polymer solutions, and Langmuir-Blodgett films.  相似文献   

Pulmonary alveolar hypoxia: release of prostaglandins and other humoral mediators   总被引：6，自引：0，他引：6  

S I Said  T Yoshida  S Kitamura  C Vreim 《Science (New York, N.Y.)》1974,185(4157):1181-1183

Hypoxic ventilation of isolated perfused cat lungs caused the frequent appearance in pulmonary perfusates of biologically active substances, which included prostaglandins or prostaglandin-like compounds. In anesthetized cats, inhibition of prostaglandin biosynthesis with infusions of aspirin (more than 50 milligrams per kilogram) reduced the pulmonary vasoconstrictor and bronchoconstrictor responses to hypoxic breathing.  相似文献   

Compound ocellus of a starfish: its function     

Yoshida M  Ohtsuki H 《Science (New York, N.Y.)》1966,153(3732):197-198

The relative effect of light in inducing downward movements of the tips of isolated arms of Asterias amurensis is maximal at 485 millimicrons when the compound ocellus is intact; at 504 millimicrons when the ocellus has been removed. This finding suggests the coexistence of two photoreceptive systems, ocellar and nonocellar.  相似文献   

Induction of inflammatory arthropathy resembling rheumatoid arthritis in mice transgenic for HTLV-I   总被引：28，自引：0，他引：28  

Y Iwakura  M Tosu  E Yoshida  M Takiguchi  K Sato  I Kitajima  K Nishioka  K Yamamoto  T Takeda  M Hatanaka 《Science (New York, N.Y.)》1991,253(5023):1026-1028

Human T cell leukemia virus type-I (HTLV-I) is the etiologic agent of adult T cell leukemia and has also been suggested to be involved in other diseases such as chronic arthritis or myelopathy. To elucidate pathological roles of the virus in disease, transgenic mice were produced that carry the HTLV-I genome. At 2 to 3 months of age, many of the mice developed chronic arthritis resembling rheumatoid arthritis. Synovial and periarticular inflammation with articular erosion caused by invasion of granulation tissues were marked. These observations suggest a possibility that HTLV-I is one of the etiologic agents of chronic arthritis in humans.  相似文献   

Evidence for brainstem structures participating in oculomotor integration     

Nakamagoe K  Iwamoto Y  Yoshida K 《Science (New York, N.Y.)》2000,288(5467):857-859

The cerebellar flocculus has been implicated in vestibulo-oculomotor control. One major central input to this structure originates from brainstem cells in the paramedian tract (PMT), whose function is unknown. Here it is reported that PMT cells in the pons carry vestibular and eye movement signals and their pharmacological inactivation produces a leaky integrator combined with vestibular imbalance. The results suggest that PMT cells provide the cerebellum with sensory and motor signals that are essential for velocity-to-position integration, a common premotor process that is required in all motor systems.  相似文献