Jan., I954. ]
CURRENT ToPics
picture produced on the screen of the image amplifier to a number of medical classroom receivers. Because this will be close-circuit television more lines will be scanned per inch--giving more detail. The image amplifier has gone into the movies, too. It has been arranged with a special lens system and a special 16-mm. movie camera so that the doctor can record the action, say, of the heart or the duodenum for several seconds. Besides being a more fruitful mode of diagnosis, it spares the patient a long-time exposure to X-rays. In its present commercial form the image amplifier is associated with the spot-film device. This is a mechanism by which, when the fluoroscopist sees something he wishes to record, a film holder is advanced quickly by a system of levers to that area and the exposure made. The image amplifier also became, last year, a traveler. One of the first commercial models made the trip to Copenhagen, Denmark for demonstration before the International Congress of Radiologists--the most important convention of this branch of the medical profession. It also has taken to the highway. A large trailer--such as is used for mobile tuberculosis survey units--has been fitted with an image amplifier and is on tour to the major cities of the United States to give doctors a firsthand chance to see what it can do. Taking X-ray apparatus to the doctor or clinic for study is in itself a new idea. Medical men are coming forward with jobs for the image amplifier not contemplated in the earlier stages of its development. It appears that it may have an important function in connection with polio epidemics. One group of doctors are using it to observe the state of a polio-patient's lungs to
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determine whether he should be given the assistance of the iron lung--a step that, when it becomes necessary, must be taken quickly.
Vacuum Ultra-Violet Spectrometer. --Solar rays found only in the outer atmosphere are reproduced artifically by a new device which will simplify scientific exploration in a little-known region of fundamental research. The device, developed by engineers of the General Electric Company, records the reaction of various crystals to vacuum ultra-violet radiation, the more powerful cousin of ordinary ultraviolet rays that cause sunburn. A characteristic peculiar to vacuum ultra-violet light is its rapid absorption by air, with the result that the rays never penetrate the earth's layer of atmosphere. The company's General Engineering Laboratory developed the device as an improvement over existing bulky and complex apparatus. G - E scientists say that although it produces radiation found only at altitudes of 150 to 200 miles, the new research tool is not intended as a means of studying the problems of space travel. T he y say the extensive basic research made possible by the device may lead instead to such developments as an improved phosphor for television picture tubes, better fluorescent lamps, new electronic devices, and a better device for measuring the exposure of human beings to the damaging radiation from atomic bomb blasts. Although not generally available at this time, this equipment, called a vacuum ultra-violet spectrometer, was designed for maximum flexibility of use. Possible applications include the making of optical absorption measurements on crystals, liquids and gases,
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CURRENT TOPICS
photoconductivity measurements, and for determination of the excitation spectra of phosphors. It also may be used for studies with ordinarT ultraviolet light. Source of the vacuum ultra-violet radiation is a low voltage, high-current hydrogen discharge lamp. The equipment is mounted on a movable table weighing only about 600 lb. and measuring approximately four by five feet. It operates on ll0-volt electrical current. New Use for Cranberries.--A new method for purifying crude ursolic acid, a drug obtained from cranberries, has been developed b y University of Wisconsin pharmaceutical researchers who have also converted the acid into a compound which may be useful in prolonging the effect of penicillin injections. The Wisconsin researchers who developed the method are Prof. Lloyd M. Parks and Betty Y. T. Wu. The substance known as ursolic acid is found in the shiny skins of a number of fruits, among them apples and cranberries, and has possible use in the formulation of emulsions in drug and cosmetic manufacture. The Wisconsin researchers also produced an amino derivative of ursolic acid which they believe might prove useful in lengthening the effects of penicillin injected into body muscles. A problem always encountered in administering penicillin is that the penicillin is absorbed too rapidly by the body. A drug named procaine is often injected with penicillin to slow absorption, and Parks and Wu believe that the amino derivative might be equally useful for prolonging the activity of penicillin in the body. The research at Wisconsin was supported by the National Cranberry. Association which now has a pilot plant for the experimental production of ursolic acid in operation at Hanson,
IJ. F. [.
Dental Technician Develops Artificial Mouth.--The brain-child of a Navy enlisted dental technician won second prize when it was placed in competition with other exhibits at the convention of the American Dental Association in Cleveland. The exhibit displayed a machine designed to simulate cavity-producing conditions in the human mouth, originally conceived by Dentalman Barnard A. Yocke during his work in the Dental Research Facility of the Naval Medical Center, Bethesda, Md. Yocke had become intrigued by the idea of being able to watch a cavity as it develops in a tooth and, on his own, developed a crude machine for simulating caries conditions from spare parts and discarded equipment. Naval consultants took notice and gave his work official sanction and expert guidance. The result is a "mouth" (with teeth) that simulates breathing, living pulp chambers, a flow of saliva, body temperature and chewing motions. It hasn't learned to talk---vet. New Underwater Acoustic Lab in O p e r a t i o n . - - T h e Naval Ordnance Laboratory recently announced that a floating facility for studying longrange, underwater, sound-pickup devices is now in operation on a Patuxent River reservoir north of the Capital, replacing a previous one on nearby Lake Barcroft. Testing is performed from a covered barge with an enclosed well through which experimental devices can be lowered to the bottom of the reservoir. The facility is equipped to work with frequencies ranging from sub-audio to high ultrasonic and will be used for testing sound projectors, hydrophones and transducers, as well as for conducting basic research in the