Solid State Nuclear Magnetic Resonance

1H, 13C and 31P MAS NMR studies of lyophilized brain tumors

from ScienceDirect Publication: Solid State Nuclear Magnetic Resonance

Publication year: 2010
Source: Solid State Nuclear Magnetic Resonance, In Press, Accepted Manuscript, Available online 11 January 2010
R., Marszałek , M., Pisklak , D., Horsztyński , I., Wawer

¹H, ¹³C and ³¹P magic angle spinning magnetic resonance spectra (MAS NMR) of lyophilized brain tissue specimens were recorded. Among the 35 cases of brain tumors there were 24 glioblastomas, 7 meningiomas and a few other types. ¹H NMR measurements were performed with a MAS speed of 33 kHz. The intense CH₃, CH₂ and CH=peaks in the ¹H spectrum result from fatty acid residues of phospholipids, which are „mobile enough” besides the anhydrous environment. ¹³C CPMAS spectra revealed the resonances of creatine and guanidine carbons; the high intensity signals arise from carbonyl groups and methylene carbons of lipids. In particular we found a fraction of mobile lipids, characterized by narrow resonances and long T_1ρ^H. Overlapped resonances of phospholipids head groups contributed to the peak at 4-7 ppm in the ³¹P MAS NMR spectra. Our results indicate that ¹H and ¹³C MAS NMR are able to characterize tumor types: differentiate glioblastomas from meningiomas and shed light on tumor biochemical characteristics. However, water soluble metabolites are not observed and macromolecules yield broad overlapped resonances. Generally, lyophilization significantly decreases discriminative potential of NMR analysis.

Three-pulse spin echo signals from quadrupolar nuclei in magnetic materials

from ScienceDirect Publication: Solid State Nuclear Magnetic Resonance

Publication year: 2010
Source: Solid State Nuclear Magnetic Resonance, In Press, Accepted Manuscript, Available online 22 January 2010
S.N., Polulyakh , N.A., Sergeev , A.I., Gorbovanov , V.N., Berzhansky

The time evolutions of the three-pulse spin echo signals from quadrupolar nuclei ⁶³Cu and ⁵³Cr in ferromagnetic CuCr₂S₄:Sb have been investigated at the temperature T=77 K. The experimental results were well explained by the developed theory of the time evolutions of the three-pulse echoes. The main assumption of this theory is the assumption that the temporal fluctuations in the electron magnetization lead to the fluctuations in the hyperfine and quadrupole interaction Hamiltonians.