Letter: Galactosemia and galactonolactone: further biochemical observations     

T B Friedman  R J Yarkin  C R Merril 《Science (New York, N.Y.)》1974,183(126):764-766

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Interferon binding: the first step in establishment of antiviral activity   总被引：17，自引：0，他引：17  

R M Friedman 《Science (New York, N.Y.)》1967,156(783):1760-1761

Chick cells incubated at 1 degrees C with interferon fail to develop antiviral activity, but this activity appears subsequent to a 7-hour incubation at 37 degrees C after removal of interferon by repeated washings. Treatment with actinomycin D blocks the development of the latter activity. Cells incubated with interferon at 1 degrees C for up to 1 hour and then washed and incubated for 2 hours at 37 degrees C develop a degree of antiviral activity proportional to the concentration of interferon at initial incubation; at any concentration, the antiviral activity increased with the duration of initial incubation at 1 degrees C, but a maximal response was reached at 10 or 20 minutes. Treatment with trypsin after incubation with interferon at 1 degrees C inhibited development of antiviral activity. Interferon is rapidly bound to a superficial cell site, and this binding is necessary for development of antiviral activity in chick cells.  相似文献   

Irradiated food     

Friedman ST 《Science (New York, N.Y.)》1984,225(4662):566-568

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X-ray Survey of Centaurus A     

Byram ET  Chubb TA  Friedman H 《Science (New York, N.Y.)》1970,169(3943):366-368

An x-ray survey of Centaurus A has given marginal evidence of its x-ray flux. If taken as an upper limit on inverse Compton x-rays generated by scattering interactions between relativistic electrons and cosmological background photons, the observation implies an upper limit of close to 3 degrees K for the background radiation temperature.  相似文献   

Retention of plutonium and americium by rock     

Fried S  Friedman AM  Atcher R  Hines J 《Science (New York, N.Y.)》1977,196(4294):1087-1089

The relative migration ratio of plutonium in various rocks is approximately 100 micrometers per meter of waterflow; the corresponding migration ratio for americium is about 500 micrometers per meter of water flow. Under these conditions radioactive decay will have taken place to such an extent that little plutonium and americium can reach the external environment from a well-designed and isolated geological repository site.  相似文献   

Deuterium: natural variations used as a biological tracer     

J D Gleason  I Friedman 《Science (New York, N.Y.)》1970,169(950):1085-1086

The suggestion is made that isotope tracing be carried out by monitoring the natural variations in deuterium concentrations. As an example, the natural variations in deuterium concentrations between food and water collected in Illinois and food and water collected in Colorado were used to determine the residence time of water in the blood and urine of rats. We observed not only a 5(1/2)-day turnover time of water in the blood and urine, but also evidence for the influx of water vapor from the atmosphere through the lungs into the blood.  相似文献   

Trehalose regulation of glucose-6-phosphate hydrolysis in blowfly extracts     

Friedman S 《Science (New York, N.Y.)》1968,159(3810):110-111

The presence of trehalose enhances the rate of glucose-6-phosphate hydrolysis in extracts of fat body and other tissues of adult Phormia regina Meigen. The activation appears to be specific, and increasing the concentration of trehalose changes both V(max) and K(m) for glucose-6-phosphate. There is, however, no easily recognizable phosphotransferase in the extract.  相似文献   

Sieving behavior of a series membrane system     

Friedman MH  McCally RL  Bresler EH  Mason EA  Wendt RP 《Science (New York, N.Y.)》1972,175(4021):556-558

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The draft: why not everybody?     

Friedman J  Parnall E  Fox DL 《Science (New York, N.Y.)》1966,153(3733):249

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Ordered and dynamic assembly of single spliceosomes     

Hoskins AA  Friedman LJ  Gallagher SS  Crawford DJ  Anderson EG  Wombacher R  Ramirez N  Cornish VW  Gelles J  Moore MJ 《Science (New York, N.Y.)》2011,331(6022):1289-1295

The spliceosome is the complex macromolecular machine responsible for removing introns from precursors to messenger RNAs (pre-mRNAs). We combined yeast genetic engineering, chemical biology, and multiwavelength fluorescence microscopy to follow assembly of single spliceosomes in real time in whole-cell extracts. We find that individual spliceosomal subcomplexes associate with pre-mRNA sequentially via an ordered pathway to yield functional spliceosomes and that association of every subcomplex is reversible. Further, early subcomplex binding events do not fully commit a pre-mRNA to splicing; rather, commitment increases as assembly proceeds. These findings have important implications for the regulation of alternative splicing. This experimental strategy should prove widely useful for mechanistic analysis of other macromolecular machines in environments approaching the complexity of living cells.  相似文献