Results 331 to 340 of about 165,169 (375)
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Canadian Journal of Biochemistry and Physiology, 1957
Oxygen uptake could not be demonstrated when uracil, uridine, or uridylic acid and various supplements were incubated with rat liver preparations. Attention was directed towards the likelihood that the initial step of uracil catabolism in mammals is a reduction such as occurs in yeasts. Various techniques were employed to measure the possible reduction
Bruce McKay +2 more
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Oxygen uptake could not be demonstrated when uracil, uridine, or uridylic acid and various supplements were incubated with rat liver preparations. Attention was directed towards the likelihood that the initial step of uracil catabolism in mammals is a reduction such as occurs in yeasts. Various techniques were employed to measure the possible reduction
Bruce McKay +2 more
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Physical Chemistry Chemical Physics, 2007
We investigate the photochemistry and photodissociation dynamics of uracil by two-colour photofragment Doppler spectroscopy and by two-colour slice imaging at excitation wavelengths between 268 and 235 nm. We observe the loss of a hydrogen atom upon excitation into the pipi* state.
Christof Schon +4 more
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We investigate the photochemistry and photodissociation dynamics of uracil by two-colour photofragment Doppler spectroscopy and by two-colour slice imaging at excitation wavelengths between 268 and 235 nm. We observe the loss of a hydrogen atom upon excitation into the pipi* state.
Christof Schon +4 more
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Uracil Photoproducts from Uracil Irradiated in Ice
Science, 1969Two new products were isolated from uracil irradiated with ultraviolet light in frozen aqueous solution. As judged by mass, nuclear magnetic resonance, and ultraviolet and infrared spectra, one is a photopolymer, U 3 , and the structure of the other is probably 6-4′-[pyrimidin-2′-one]-uracil.
S. Y. Wang, M. N. Khattak
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Drugs & Aging, 2001
Tegafur is a prodrug of the antineoplastic agent fluorouracil, and is administered in a 1:4 molar ratio with the fluorouracil modulator uracil. Oral tegafur/uracil 300 mg/m(2)/day plus calcium folinate 75 or 90 mg/day for 28 days every 35 days was as effective as intravenous (IV) fluorouracil 425 mg/m(2)/day plus folinic acid 20 mg/m(2)/day for 5 days ...
Karen L. Goa, Keri Wellington
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Tegafur is a prodrug of the antineoplastic agent fluorouracil, and is administered in a 1:4 molar ratio with the fluorouracil modulator uracil. Oral tegafur/uracil 300 mg/m(2)/day plus calcium folinate 75 or 90 mg/day for 28 days every 35 days was as effective as intravenous (IV) fluorouracil 425 mg/m(2)/day plus folinic acid 20 mg/m(2)/day for 5 days ...
Karen L. Goa, Keri Wellington
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Canadian Journal of Chemistry, 1980
The sonolysis of uracil (1) has been studied at 630 kHz in the presence of air, oxygen, nitrogen, and argon. The degradation products were identified by gc–ms analysis. Under aerated conditions the following products were found: uracil glycols (7), isobarbituric acid (8), N-formyl-N′-glyoxylurea (6), 5-hydroxyhydantoin (9), dialuric acid (10), alloxan
R.G. Sutherland +2 more
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The sonolysis of uracil (1) has been studied at 630 kHz in the presence of air, oxygen, nitrogen, and argon. The degradation products were identified by gc–ms analysis. Under aerated conditions the following products were found: uracil glycols (7), isobarbituric acid (8), N-formyl-N′-glyoxylurea (6), 5-hydroxyhydantoin (9), dialuric acid (10), alloxan
R.G. Sutherland +2 more
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Controlling Photorelaxation in Uracil with Shaped Laser Pulses: A Theoretical Assessment.
Journal of the American Chemical Society, 2017The RNA nucleobase uracil can suffer from photodamage when exposed to UV light, which may lead to severe biological defects. To prevent this from happening in most cases, uracil exhibits an ultrafast relaxation mechanism from the electronically excited ...
D. Keefer +3 more
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Uracil-DNA Glycosylases and DNA Uracil Repair
1989Publisher Summary This chapter reviews the DNA uracil repair and uracil–DNA glycosylases (UDG). The major source of DNA uracil in prokaryotic and eukaryotic cells is transient incorporation of dUMP during replication. This replicative uracil is quickly repaired by UDG, apyramidinic/apurinic (AP) endonucleases, and other enzymes of excision repair ...
O.N. Aprelikova, N.V. Tomilin
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The Photochemistry of Uracil: A Reinvestigation
Photochemistry and Photobiology, 2010AbstractResults from a re‐examination of the photochemical reactions undergone by uracil (Ura) are presented. Irradiation of Ura in frozen aqueous solution at −78.5°C produces two diastereomeric (6‐4) products, namely the cis and trans isomers of 5‐hydroxy‐6‐4′‐(pyrimidin‐2′‐one)‐5,6‐dihydrouracil.
Martin D. Shetlar, Vladimir J. Basus
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Specificities and kinetics of uracil excision from uracil-containing DNA oligomers by Escherichia coli uracil DNA glycosylase [PDF]
Biochemistry, 1991 Uracil DNA glycosylase excises uracil residues from DNA that can arise as a result of deamination of cytosine or incorporation of dUMP residues by DNA polymerase. We have carried out a detailed study to define the specificities and the kinetic parameters for its substrates by using a number of synthetic oligodeoxyribonucleotides of varying lengths and ...
Umesh Varshney, Johan H. van de Sande
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Stable Triplet of Uracil−Uracil Basepairs in a Small Antisense RNA
Journal of the American Chemical Society, 2005The interaction between ant (antirepressor) mRNA and its antisense RNA, sar (small antisense RNA), is important in regulation of the development of bacteriophage P22. Sar is 68-69 nucleotides in length and is believed to consist of two hairpin structures separated by a small inter-hairpin region, followed by a short 3' tail [Schaefer and McClure RNA ...
Yiping Zhan, Gordon S. Rule
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