Results 231 to 240 of about 320,692 (287)

J(13C13C) in allylmetal complexes

Journal of Organometallic Chemistry, 1982
Abstract The J(13C13C) coupling constants of simple allyl compounds of nickel, chromium, magnesium and lithium have been determined on natural abundance samples. In transition metal complexes 1J(13C13C) is reduced to 41 Hz (Ni) whilst in allyllithium it is 58.7 Hz.
Reinhard Benn, Anna Rufińska
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1J(13C, 13C) in (η4-butadien)übergangsmetallkomplexen

Journal of Organometallic Chemistry, 1987
The indirect scalar spin-spin coupling constant 1J(13C, 13C) has been determined in dissolved (η4-diene)transition metal complexes using natural-abundance samples of complexes of Zr, Hf, Th, Mo, W, Fe, and Co. 1J(13C, 13C) is a sensitive probe for metal-diene bonding in such complexes: In planar η4-s-cis-diene compounds with similar carbon bond lengths,
Reinhard Benn, Anna Rufińska
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13C Scrambling of [5-13C]5-cyclodecynone

Tetrahedron Letters, 2000
Scrambling of [5-13C]5-cyclodecynone occurs as a result of acidic conditions that preclude its rapid consumption.
Michael F Wempe, John R Grunwell
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M1 from factors of 13C, 13C and 15N

Nuclear Physics A, 1981
Abstract Core polarization effects are shown to explain both the reduction of the second peak of the M1 form factor of 13 C(e,e) 13 C and the enhancement of that of 12 C(e,e') 12 C (1 + , T = 1, 15.1 MeV) over the Cohen-Kurath predictions.
T. Suzuki, H. Hyuga, A. Arima, K. Yazaki
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13C-13C Coupling-Constants in Carboxylate Esters

Microchemical Journal, 1993
Abstract Isotopic enrichment or a multipulse NMR experiment (INADEQUATE) was utilized to measure the 13 C- 13 C coupling constants for a collection of carboxylate esters. Significantly different values were measured for the C 2 C 3 bond of endo - and exo -2-norbornyl acetates. The 13 C- 13 C coupling constants for the CαCO bond of substituted
R.M. Jarret, L. Cusumano, M. Dinztner, M. Fortin, K. Pothier, J. Connolly, M. Biondi, T. Morrison   +7 more
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Fusion cross sections for 12C + 12C, 12C + 13C and 13C + 13C at low energies

Nuclear Physics A, 1982
Abstract Fusion cross sections for 12 C + 12 C and 12 C + 13 C have been measured by the total-γ-ray- yield method over the c.m. energy intervals 4.2–7.0 MeV and 3.1–6.7 MeV, respectively. Comparing the present 12 C + 12 C fusion cross sections with those obtained previously by various methods, the discrepancies between data are clarified.
Binay Dasmahapatra, Bibiana Čujec, Fouad Lahlou   +2 more
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Side chain dynamics monitored by 13C-13C cross-relaxation

Journal of Biomolecular NMR, 2004
A method to measure (13)C-(13)C cross-relaxation rates in a fully (13)C labeled protein has been developed that can give information about the mobility of side chains in proteins. The method makes use of the (H)CCH-NOESY pulse sequence and includes a suppression scheme for zero-quantum (ZQ) coherences that allows the extraction of initial rates from ...
Houben, K., Boelens, R.
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Oxidation of exogenous [13C]galactose and [13C]glucose during exercise

Journal of Applied Physiology, 1995
The present study examined the oxidation of exogenous galactose or glucose during prolonged submaximal cycling exercise. Eight highly trained volunteers exercised on two occasions on a cycle ergometer at 65% of maximal workload for 120 min, followed by a 60-min rest period and a second exercise bout of 30 min at 60% maximal workload.
D P, Leijssen, W H, Saris, A E, Jeukendrup, A J, Wagenmakers   +3 more
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A Method for Obtaining 13C Isotopomer Populations in 13C-Enriched Glucose

Analytical Biochemistry, 1994
13C NMR analysis of 13C-enriched glucose containing multiple isotopomers is hampered by chemical shift similarities of several carbon resonances and by the presence of two anomeric forms. A convenient and quantitative method of enzymatically oxidizing glucose to gluconate in tissue and perfusate extracts is presented.
J G, Jones, G L, Cottam, B C, Miller, A D, Sherry, C R, Malloy   +4 more
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Comparative absorption of [13C]glucose and [13C]lactose by premature infants

The American Journal of Clinical Nutrition, 1990
Oxidation of orally administered [13C]glucose and [13C]lactose and fecal recovery of malabsorbed substrates were determined in two groups of premature infants. Eighteen studies were performed with six infants at Johns Hopkins Hospital (JHH); 24 studies were performed with nine infants at Columbus Children's Hospital (CCH).
R D, Murray, T W, Boutton, P D, Klein, M, Gilbert, C L, Paule, W C, MacLean   +5 more
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