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991.
992.
NISHIMURA ET HAMILTON HB KOBARA TY TAKAHARA S OGURA Y DOI K 《Science (New York, N.Y.)》1959,130(3371):333-334
The heterozygous carrier state of a rare hereditary disease, acatalasemia, has been defined biochemically. Affected homozygotes have no blood catalase activity, whereas heterozygotes show activities intermediate between this inactivity and the activity of normal controls, without overlap. Pedigrees show a high frequency of consanguineous marriages. 相似文献
993.
Identification and characterization of a neuron-specific nuclear antigen in Drosophila 总被引:7,自引:0,他引:7
An antigen found only in neuronal nuclei of Drosophila melanogaster is revealed by staining with a monoclonal antibody (Mab44C11). This antigen appears early in development, before neurons show any other signs of antigenic or morphologic differentiation, and persists throughout development. This nuclear staining permits reliable detection of neurons in developmental studies of wild-type and mutant flies. Protein immunoblot analyses and immune precipitation experiments show that the neuronal nuclear antigen is a 50-kilodalton polypeptide. 相似文献
994.
Heparin affinity: purification of a tumor-derived capillary endothelial cell growth factor 总被引:73,自引:0,他引:73
Y Shing J Folkman R Sullivan C Butterfield J Murray M Klagsbrun 《Science (New York, N.Y.)》1984,223(4642):1296-1299
A tumor-derived growth factor that stimulates the proliferation of capillary endothelial cells has a very strong affinity for heparin. This heparin affinity makes it possible to purify the growth factor to a single-band preparation in a rapid two-step procedure. The purified growth factor is a cationic polypeptide, has a molecular weight of about 18,000, and stimulates capillary endothelial cell proliferation at a concentration of about 1 nanogram per milliliter. 相似文献
995.
Smith JB Lamanna MC Lacovara KJ Dodson P Smith JR Poole JC Giegengack R Attia Y 《Science (New York, N.Y.)》2001,292(5522):1704-1706
We describe a giant titanosaurid sauropod dinosaur discovered in coastal deposits in the Upper Cretaceous Bahariya Formation of Egypt, a unit that has produced three Tyrannosaurus-sized theropods and numerous other vertebrate taxa. Paralititan stromeri is the first tetrapod reported from Bahariya since 1935. Its 1.69-meter-long humerus is longer than that of any known Cretaceous sauropod. The autochthonous scavenged skeleton was preserved in mangrove deposits, raising the possibility that titanosaurids and their predators habitually entered such environments. 相似文献
996.
Terminology of vertebrate melanin-containing cells: 1965 总被引:1,自引:0,他引:1
T B Fitzpatrick W C Quevedo A L Levene V J McGovern Y Mishima A G Oettle 《Science (New York, N.Y.)》1966,152(718):88-89
997.
We demonstrate electron-stimulated migration for carbon monoxide (CO) molecules adsorbed on the Pd(110) surface, which is initiated by the excitation of a high-frequency (HF) vibrational mode (C-O stretching mode) with inelastic tunneling electrons from the tip of scanning tunneling microscopy. The hopping phenomenon, however, cannot be detected for CO/Cu(110), even though the hopping barrier is lower than in the CO/Pd(110) case. A theoretical model, which is based on the anharmonic coupling between low-frequency modes (the hindered-translational mode related to the lateral hopping) and the HF mode combined with electron-hole pair excitation, can explain why the hopping of CO is observed on Pd(110) but not on Cu(110). 相似文献
998.
Yeh PY 《Science (New York, N.Y.)》1955,121(3150):707-708
999.
A toxin isolated from apple fruit tissue infected by Erwinia amylovora is 98 percent galactose in polymeric form, 0.375 percent protein, and has an average molecular weight of approximately 165,000. Young shoots of rosaceous, but not nonrosaceous, species wilt in a manner characteristic of the disease when placed in toxin solutions with concentrations as low as 10 micrograms per milliliter. Varieties of apple and pear susceptible to Erwinia amylovora wilt in 1 to 3 hours, whereas resistant varieties display symptoms 12 to 24 hours after treatment. 相似文献
1000.