The deuteron fast Fourier transform (FFT) spectra of the ring deuterated nematogens para-azoxyanisole (PAA-d8) and p-methoxybenzylidene p-n-butylaniline (MBBA-d8) have been studied as a function of temperature. An interpretation of the spectra is presented. It is based on the assumption of nonequivalent deuterons, a twist angle φ between the planes of the benzene rings, and an asymmetry order parameter δ in addition to the usual nematic order parameter S. The temperature dependences of δ and φ have been obtained.

No abstract

Plasma from patients with malignant and benign primary intracranial neoplasms and from healthy control subjects has been examined using proton (1H) and carbon-13 nuclear magnetic resonance (NMR) spectroscopy. Some features in the spectra of plasma from patients with malignant tumors differ significantly (p less than 0.01) from the corresponding features in the spectra of plasma from control subjects and from patients with benign tumors. The NMR spectral parameters vary consistently with the Kernohan grade of astrocytoma, which may suggest that they give a measure of tumor growth kinetics. The observed spectral differences are shown to be due to elevated levels of monounsaturated and polyunsaturated fatty acid residues in the plasma of cancer patients. It is proposed that these lipid residues arise from cell membranes shed from cells in growing tumors. The ability to follow tumor growth kinetics directly may be of considerable importance in elucidating the effects of primary intracranial neoplasm therapy.

No abstract

No abstract