| ultramicroscope | <instrument, microscopy> A term applied to particles less than 0.1 ~m in diameter, hence too small to be truly resolved by the light micro- scope. Under the ultramicroscope they look like stars in the sky. Their differences in size are merely indicated by differences in brightness. (05 Aug 1998) |
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| ultramicroscopic | <optics> Particles which, although visible in the ultramicroscope, are too small to be resolved by visible light. This places their size between 0.2 Lm and 0.005 Lm. (05 Aug 1998) |
| ultramicrotome | A microtome used in cutting sections 0.1 um thick, or less, for electron microscopy. (05 Mar 2000) |
| ultramicrotomy | The cutting of ultrathin sections for electron microscopy by use of an ultramicrotome. (05 Mar 2000) |
| ultramontanism | The principles of those within the Roman Catholic Church who maintain extreme views favoring the pope's supremacy; so used by those living north of the Alps in reference to the Italians; rarely used in an opposite sense, as referring to the views of those living north of the Alps and opposed to the papal claims. Cf. Gallicanism. Origin: Cf. F. Ultramontanisme. Source: Websters Dictionary (01 Mar 1998) |
| ultrared | <physics> Situated beyond or below the red rays; as, the ultrated rays of the spectrum, which are less refrangible than the red. Origin: Pref. Ultra- + red. Source: Websters Dictionary (01 Mar 1998) |
| ultrashortwave diathermy | Shortwave diathermy in which the wavelength is under 10 meters. (05 Mar 2000) |
| ultrasonic | Relating to energy waves similar to those of sound but of higher frequencies (above 30,000 Hz). Origin: ultra-+ L. Sonus, sound (05 Mar 2000) |
| ultrasonic cardiography | Echocardiography is a diagnostic test which uses ultrasound waves to make images of the heart chambers, valves and surrounding structures. It can measure cardiac output and is a sensitive test for inflammation around the heart (pericarditis). It can also be used to detect abnormal anatomy or infections of the heart valves. (12 Dec 1998) |
| ultrasonic cephalometry | Measurement of the foetal head by ultrasound. (05 Mar 2000) |
| ultrasonic egg recovery | Obtaining an egg for in vitro fertilization by means of an ultrasonically guided needle aspiration of ovarian follicles; may be performed transvesically or via the cul-de-sac. (05 Mar 2000) |
| ultrasonic lithotresis | The demolition of calculi by high frequency sound waves. (05 Mar 2000) |
| ultrasonic microscope | <instrument> A microscope that has lenses designed to use acoustic energy so that the ultrasonic wavelengths may be utilised; by means of transducers, the information is translated to a form that may be visualised or recorded. (05 Mar 2000) |
| ultrasonic nebuliser | A humidifier using high-frequency electricity to power a transducer that vibrates 1,350,000 times per second and changes water up into particles 0.5 to 3 um in size in its nebulizing chamber; used in inhalation therapy. (05 Mar 2000) |
| ultrasonic rays | See: ultrasonic. (05 Mar 2000) |