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At least 433 records · Page 24Linked to original sources
PubMed1988

[Study of conformation structure and molecular interactions of rosamycin by infrared spectrum analysis].

IR spectra of rosamycin and its solutions in inert (CCl4 and C2Cl4), proton acceptor (tetrahydrofuran, hexametapol and diethylamine) and proton donor (CHCl3 and CH3OD) solvents were studied at various concentrations (0.1 to 0.001 mol/l) and temperatures (20 to 100 degrees C) in the region of the vC = O and vOH absorption bands (1600-1800 and 3200 3650 sm 1). It was found that the absorption bands at 3480 and 3560 sm-1 observed in the spectra of rosamycin diluted solutions in the inert solvents referred to variations of vOH...N of the aminosugar fragment and to vOH...O = C of the ester group of the macrocycle. Bands at 1697 and 1717 sm-1 referred to vC = O of the ketone and aldehyde carbonyl groups and band at 1728 sm-1 referred to vC = O of the ester group whose carbonyl was involved in the C = H...HO intramolecular hydrogen bond. Intensity of vC = O band (1745 sm-1) of the free ester group was nought. However, it increased with using the proton acceptor solvents. OH...N and OH...O = C intramolecular hydrogen bonds stabilized rosamycin molecule conformation. Mechanism of rosamycin interaction with the proton donor and acceptor molecules was elucidated. It was shown that tertiary nitrogen was the center of rosamycin molecule protonation.

Chemical Phenomena↗
PubMed1988

[Clinical application of intermediate spectrum analysis of the voice. Preliminary study].

Until now, the objective examination of the voice quality has remained confined to the laboratory. The coming out of the Brüel and Kjaer 2033 type high-resolution voice frequency analyzer led us now to realize a rapid recording and easy reading of the fundamental frequency and of the main harmonics. An objective document can thus be filed as a comparison before and after treatment. The recording relates to the intensity in terms of the frequency. The intensity is principally investigated in the linear mode, that is, in mv. The frequency is usually recorded from 0 to 1000 Hz so that one can observe the first harmonics. The retained tests in addition to the intensity and the frequency peaks are the peak enlargement, the hooks and the parasite vocal sounds.

Adult↗
PubMedDate not supplied

Headache lateralization and functional cerebral asymmetry: a task-related EEG power spectrum analysis.

Clinical evidence shows that pain, particularly without organic lesions, tends to be more frequent on the left side of the body. Concomitantly, experimental data indicate that differential sensitivity for the right and left side, the pain threshold and tolerance being usually higher in the dominant than in the non-dominant side of the body. Headache laterality was investigated in 188 consecutive chronic headache patients. Headache was lateralized in approximately 50% of the cases, with an overall right predominance (59%). However, when descriptive diagnosis was taken into consideration, lateralized pain was predominant on the left side in psychogenic headache (p less than .01), whereas somatogenic headache was more often right-sited. Since pain lateralization can hardly be explained by peripheral factors, we assumed that reduced efficiency of the non-dominant side in processing several perceptual and cognitive activities could reflect asymmetry in cerebral organization. As differential engagement of the two hemispheres by appropriate tasks can be demonstrated with the EEG, we have studied 13 chronic headache patients with quantitative EEG analysis, compared with a control group of normal subjects (n = 7). The analysis of alpha-asymmetry, during analytical and spatial tasks, revealed that chronic headache patients showed a trend toward a relative activation of the right hemisphere during both tasks, independently of descriptive diagnosis, suggesting that chronic headache might be considered a "psychosomatic continuum". We postulate that pain perception may be biased by the reduced efficiency of the right hemisphere in sensory processing, so that the sensory message may be misinterpreted or amplified as painful by higher centers, even in absence of nociceptive stimuli.

Adult↗
PubMed1987

EEG changes measured by spectrum analysis under hyperbaric conditions.

The subject of experimental, saturated dividing to 20 m depth was alertness level measured by means of spectral analysis of EEG records. Air was served as breathing mixture compressed to a given depth in closed circulating system. Altogether 49 EEG records made during compression, plateau and decompression, were analysed. Two methods of analysis were applied. "Normality ratio" combined the information from 20 different EEG values and "EEG alertness indicator" showed in three cases pathological slowing and fluctuations of the alertness. According to index of alertness, the most prominent changes were seen during the compression and decompression phase. During the plateau phase sleepiness was recorded. The applied method could provide information when slowing is due to metabolic impairment of brain activity from that of sleepiness.

Adult↗
PubMed1987

Quantitative and spectrum analysis of human mylohyoid nerves.

Histological analysis of 30 postmortem specimens of human mylohyoid nerve showed a mean fibre count of 1251 and, in each case, a bimodal fibre diameter distribution curve. No relationship was found between the fibre counts and the age, weight or sex of subjects. Counts in nerves from edentulous subjects were significantly lower (P less than 0.001) than those in nerves from dentate subjects. This apparent loss of fibres was not restricted to small diameter axons.

Female↗