Stroboscopic NMR microscopy of the carotid artery
Article Abstract:
Nuclear magnetic resonance, NMR, allows visualization of parts of the body by the nuclei of cells in the body absorbing radiowaves. Stroboscopic NMR of blood vessels allows imaging of the blood flow through the blood vessels. This is the first non-invasive technique for studying blood flow that does not require entering the skin, a cavity, or an organ of the body. Stroboscopic images of the carotid artery, one of the major arteries in the neck and head, were obtained in rats. The changes in the diameter of the arteries were correlated with changes in normal blood pressure. The local effects of drugs that cause constriction or dilation of blood vessels was studied with this technique. The vasoconstrictor, phenylephrine, did not change the diameter of the carotid artery. Phenylephrine is known to affect small arteries. However, with the vasodilator, nitroprusside, the diameter of the carotid artery was increased, although there was great variation among the rats. NMR of blood flow will be a critical technique used to understand the change of flow in cardiovascular diseases such as high blood pressure and atherosclerosis, or hardening of the arteries.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1989
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A new view on polarization microscopy
Article Abstract:
The advanced polarization microscope, Pol-Scope, enables direct and precise analysis of the molecular structure of living cells through a novel combination of novel electro-optical devices, polarization algorithms and digital image processing. Pol-Scope uses a precision universal compensator comprising of two variable retarder plates to compensate for any specimen birefringence. The specimen under observation is illuminated with nearly circular polarized light. The instrument is extremely useful for measuring optical anisotropies.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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Efficient real-time confocal microscopy with white light sources
Article Abstract:
The white-light multiple-point source method is efficient in producing real time confocal microscopic images, specially of weakly luminescent specimens, with light efficiencies of 50%. The method utilizes aperture coding techniques which ensure a lack of correlation between the different apertures. This helps in developing a light-efficient confocal microscope, without the need to place the apertures far from each other. The method can be easily incorporated into traditional confocal microscopes.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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