Dominoes and clocks: the union of two views of the cell cycle   总被引：96，自引：0，他引：96  

A W Murray  M W Kirschner 《Science (New York, N.Y.)》1989,246(4930):614-621

We review the recent advances in understanding transitions within the cell cycle. These have come from both genetic and biochemical approaches. We discuss the phylogenetic conservation of the mechanisms that induce mitosis and their implications for other transitions in the cell cycle.  相似文献   

A corticosteroid receptor in neuronal membranes   总被引：22，自引：0，他引：22  

M Orchinik  T F Murray  F L Moore 《Science (New York, N.Y.)》1991,252(5014):1848-1851

Steroids may rapidly alter neuronal function and behavior through poorly characterized, direct actions on neuronal membranes. The membrane-bound receptors mediating these behavioral responses have not been identified. [3H]Corticosterone labels a population of specific, high-affinity recognition sites (dissociation constant = 0.51 nanomolar) in synaptic membranes from an amphibian brain. These binding sites were localized by receptor autoradiography in the neuropil, outside the regions of perikarya. The affinities of corticoids for this [3H]corticosterone binding site were linearly related to their potencies in rapidly suppressing male reproductive behavior. Thus, it appears that brain membranes contain a corticosteroid receptor that could participate in the regulation of behavior.  相似文献   

Intracellular absorption difference spectrum of Limulus extra-ocular photolabile pigment   总被引：7，自引：0，他引：7  

G C Murray 《Science (New York, N.Y.)》1966,154(753):1182-1183

Microspectrophotometric measurements on single cell bodies located on the surface of the"lateral olfactory nerve" of Limulus polyphemus show they contain a photolabile pigment with a absorption-difference spectrum similar in shape to that of most other visual pigments and with a maximum absorption at 529 +/- 5 nanometers.  相似文献   

Ultrafast bond softening in bismuth: mapping a solid's interatomic potential with X-rays     

Fritz DM  Reis DA  Adams B  Akre RA  Arthur J  Blome C  Bucksbaum PH  Cavalieri AL  Engemann S  Fahy S  Falcone RW  Fuoss PH  Gaffney KJ  George MJ  Hajdu J  Hertlein MP  Hillyard PB  Horn-von Hoegen M  Kammler M  Kaspar J  Kienberger R  Krejcik P  Lee SH  Lindenberg AM  McFarland B  Meyer D  Montagne T  Murray ED  Nelson AJ  Nicoul M  Pahl R  Rudati J  Schlarb H  Siddons DP  Sokolowski-Tinten K  Tschentscher T  von der Linde D  Hastings JB 《Science (New York, N.Y.)》2007,315(5812):633-636

Intense femtosecond laser excitation can produce transient states of matter that would otherwise be inaccessible to laboratory investigation. At high excitation densities, the interatomic forces that bind solids and determine many of their properties can be substantially altered. Here, we present the detailed mapping of the carrier density-dependent interatomic potential of bismuth approaching a solid-solid phase transition. Our experiments combine stroboscopic techniques that use a high-brightness linear electron accelerator-based x-ray source with pulse-by-pulse timing reconstruction for femtosecond resolution, allowing quantitative characterization of the interatomic potential energy surface of the highly excited solid.  相似文献   

Extraterrestrial intelligence: an observational approach     

Murray B  Gulkis S  Edelson RE 《Science (New York, N.Y.)》1978,199(4328):485-492

The microwave region of the electromagnetic spectrum, a plausible regime for signals from extraterrestrial intelligences, is largely unexplored. With new technology, particularly in data processing and low-noise reception, surveys can be conducted over broad regions of frequency and space with existing antennas at flux densities plausible for interstellar signals. An all-sky, broad-band survey lasting perhaps 5 years can be structured so that even negative results would establish significant boundaries on the regime in which such signals may be found. The technology and techniques developed and much of the data acquired would be applicable to radio astronomy and deep-space communications.  相似文献   

Computational improvements reveal great bacterial diversity and high metal toxicity in soil   总被引：4，自引：0，他引：4  

Gans J  Wolinsky M  Dunbar J 《Science (New York, N.Y.)》2005,309(5739):1387-1390

The complexity of soil bacterial communities has thus far confounded effective measurement. However, with improved analytical methods, we show that the abundance distribution and total diversity can be deciphered. Reanalysis of reassociation kinetics for bacterial community DNA from pristine and metal-polluted soils showed that a power law best described the abundance distributions. More than one million distinct genomes occurred in the pristine soil, exceeding previous estimates by two orders of magnitude. Metal pollution reduced diversity more than 99.9%, revealing the highly toxic effect of metal contamination, especially for rare taxa.  相似文献   

Monodisperse FePt nanoparticles and ferromagnetic FePt nanocrystal superlattices   总被引：2，自引：0，他引：2  

Sun S  Murray CB  Weller D  Folks L  Moser A 《Science (New York, N.Y.)》2000,287(5460):1989-1992

Synthesis of monodisperse iron-platinum (FePt) nanoparticles by reduction of platinum acetylacetonate and decomposition of iron pentacarbonyl in the presence of oleic acid and oleyl amine stabilizers is reported. The FePt particle composition is readily controlled, and the size is tunable from 3- to 10-nanometer diameter with a standard deviation of less than 5%. These nanoparticles self-assemble into three-dimensional superlattices. Thermal annealing converts the internal particle structure from a chemically disordered face-centered cubic phase to the chemically ordered face-centered tetragonal phase and transforms the nanoparticle superlattices into ferromagnetic nanocrystal assemblies. These assemblies are chemically and mechanically robust and can support high-density magnetization reversal transitions.  相似文献   

Structural biology. Nuclear trafficking     

Stewart M 《Science (New York, N.Y.)》2003,302(5650):1513-1514

  相似文献   

PSITTACOSIS EPIDEMICS AND PLEOMORPHIC PROTOPLASM     

Murray E 《Science (New York, N.Y.)》1930,71(1842):417-418

  相似文献   

Earthquake potential along the northern hayward fault, california   总被引：1，自引：0，他引：1  

Burgmann R  Schmidt D  Nadeau RM  d'Alessio M  Fielding E  Manaker D  McEvilly TV  Murray MH 《Science (New York, N.Y.)》2000,289(5482):1178-1182

The Hayward fault slips in large earthquakes and by aseismic creep observed along its surface trace. Dislocation models of the surface deformation adjacent to the Hayward fault measured with the global positioning system and interferometric synthetic aperture radar favor creep at approximately 7 millimeters per year to the bottom of the seismogenic zone along a approximately 20-kilometer-long northern fault segment. Microearthquakes with the same waveform repeatedly occur at 4- to 10-kilometer depths and indicate deep creep at 5 to 7 millimeters per year. The difference between current creep rates and the long-term slip rate of approximately 10 millimeters per year can be reconciled in a mechanical model of a freely slipping northern Hayward fault adjacent to the locked 1868 earthquake rupture, which broke the southern 40 to 50 kilometers of the fault. The potential for a major independent earthquake of the northern Hayward fault might be less than previously thought.  相似文献