Temporal relation between long-lasting aftercontractions and action potentials in cat papillary muscles     

A J Kaumann  C B Olson 《Science (New York, N.Y.)》1968,161(838):293-295

Sotalol, an adrenergic-blocking and antiarrhythmic agent, increases markedly and simultaneously the duration of both action potentials and contractions in papillary muscles. The active tension is manifested as a main twitch contraction followed by a maintained low level of residual tension (aftercontraction) which persists until the terminal phase of rapid repolarization. The Strength of the aftercontraction is augmented when the extracellular concentration of calcium is increased.  相似文献   

Isolation of single-copy human genes from a library of yeast artificial chromosome clones   总被引：70，自引：0，他引：70  

B H Brownstein  G A Silverman  R D Little  D T Burke  S J Korsmeyer  D Schlessinger  M V Olson 《Science (New York, N.Y.)》1989,244(4910):1348-1351

A recently developed cloning system based on the propagation of large DNA molecules as linear, artificial chromosomes in the yeast Saccharomyces cerevisiae provides a potential method of cloning the entire human genome in segments of several hundred kilobase pairs. Most application of this system will require the ability to recover specific sequences from libraries of yeast artificial chromosome clones and to propagate these sequences in yeast without alterations. Two single-copy genes have now been cloned from a library of yeast artificial chromosome clones that was prepared from total human DNA. Multiple, independent isolates were obtained of the genes encoding factor IX and plasminogen activator inhibitor type 2. The clones, which ranged in size from 60 to 650 kilobases, were stable on prolonged propagation in yeast and appear to contain faithful replicas of human DNA.  相似文献   

VELOCITY OF CADMIUM ATOMS REGULARLY REFLECTED FROM A ROCK SALT CRYSTAL     

Ellett A  Olson HF 《Science (New York, N.Y.)》1928,68(1752):89-90

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The evolution of photosynthesis   总被引：11，自引：0，他引：11  

J M Olson 《Science (New York, N.Y.)》1970,168(930):438-446

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Brain grafts reduce motor abnormalities produced by destruction of nigrostriatal dopamine system   总被引：27，自引：0，他引：27  

M J Perlow  W J Freed  B J Hoffer  A Seiger  L Olson  R J Wyatt 《Science (New York, N.Y.)》1979,204(4393):643-647

In order to determine if brain tissue grafts can provide functional input to recipient central nervous system tissue, fetal rat dopamine-containg neurons were implanted adjacent to the caudate nucleus of adult recipients whose endogenous dopaminergic input had been destroyed. The grafts showed good survival and axonal outgrowth. Motor abnormalities, which had been induced by the destruction of the endogenous dopaminergic input to the caudate, were significantly reduced after grafting of the fetal brain tissue. These data suggest that such implants may be potentially useful in reversing deficits after circumscribed destruction of brain tissue.  相似文献   

Gulf Stream Ring Coalescence with the Gulf Stream off Cape Hatteras     

Watts DR  Olson DB 《Science (New York, N.Y.)》1978,202(4371):971-972

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Molecular hydrogen as an energy source for Helicobacter pylori     

Olson JW  Maier RJ 《Science (New York, N.Y.)》2002,298(5599):1788-1790

The gastric pathogen Helicobacter pylori is known to be able to use molecular hydrogen as a respiratory substrate when grown in the laboratory. We found that hydrogen is available in the gastric mucosa of mice and that its use greatly increased the stomach colonization by H. pylori. Hydrogenase activity in H. pylori is constitutive but increased fivefold upon incubation with hydrogen. Hydrogen concentrations measured in the stomachs of live mice were found to be 10 to 50 times as high as the H. pylori affinity for hydrogen. A hydrogenase mutant strain is much less efficient in its colonization of mice. Therefore, hydrogen present in animals as a consequence of normal colonic flora is an energy-yielding substrate that can facilitate the maintenance of a pathogenic bacterium.  相似文献   

Unidirectional spread of secondary sexual plumage traits across an avian hybrid zone     

Parsons TJ  Olson SL  Braun MJ 《Science (New York, N.Y.)》1993,260(5114):1643-1646

Theory predicts that traits under positive selection can rapidly cross a hybrid zone in spite of a substantial barrier to neutral gene flow between hybridizing taxa. An avian hybrid zone between Manacus candei (white-collared manakin) and M. vitellinus (golden-collared manakin) is reported here that displays an unusual pattern of noncoincident clines. Male secondary sexual traits of M. vitellinus have spread into populations that are genetically and morphometrically like M. candei. These birds have a lek breeding system in which male mating success is highly skewed, suggesting that sexual selection is driving male sexual traits across the zone.  相似文献   

Studies on the mode of action of vitamin k     

Olson RE  Philipps GR 《Science (New York, N.Y.)》1967,158(3800):533

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THE EFFECT OF X RAYS ON CHEMICAL REACTIONS     

Olson AR 《Science (New York, N.Y.)》1922,56(1443):231

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