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845 [1381] FLEROV
LI [1382] Palade was awarded a share of the Nobel Prize for physiology and medicine in 1974. [1381] FLEROV, Georgii Nikolaevich Soviet physicist Born: March 2, 1913 Flerov, who had been educated at the Leningrad Industrial Institute of Science, was among those Russians who early began the investigation of nuclear fission. In 1941 he discovered that uranium did not undergo fission only when bom barded with neutrons. It also did so (excessively slowly) even without out side interference, in what has come to be called “spontaneous fission.” Sponta neous fission is an important method of breakdown among the transuranium ele ments formed through nuclear bombard ment since the 1940s. Flerov has worked on these trans uranium elements, too, and in 1965 he announced the formation of an isotope of element 104, the most complicated el ement formed to that date. Tlie element has been unofficially named kurcha tovium in honor of Kurchatov [1261]; but Flerov’s work has not yet been confirmed and the name remains unofficial. American scientists, forming 104 by other methods, have suggested the name rutherfordium instead. [1382] LI, Choh Hao (lee) Chinese-American biochemist
1913
Li graduated from the University of Nanking in 1933. He emigrated to the United States in 1935 and took up grad uate studies at the University of Califor nia, where he earned his Ph.D. and then joined the faculty. He is now director of the Hormone Research Laboratories there.
Li’s professional life has been spent al most entirely on the study of the hor mones of the pituitary gland, a study that had been initiated earlier by men like Houssay [1115]. Li and his group iso lated a number of protein hormones from the pituitary; one of them was adrenocorticotrophic hormone, better known by the initials ACTH. This stimu lates the activity of the adrenal cortex, increasing the output of the corticoids. For that reason administration of ACTH achieves, indirectly, what the adminis tration of a corticoid such as cortisone achieves directly. When Hench [1188] discovered the ameliorative effect of cor tisone on rheumatoid arthritis, he found a similar effect for ACTH and that, too, gained fame with the lay public as a wonder drug. Other pituitary hormones serve to stimulate the activity of such glands as the thyroid and the gonads. The pituitary seems to be a general coordinator for the hormones produced elsewhere and to serve, almost, as the “master gland” of the body. The protein hormones, like those of the pituitary, resist chemical charac terization more than the hormones of simpler structure, like adrenalin, thyrox ine, and the various steroid hormones. Nevertheless, with the development of Sanger’s [1426] technique for determin ing the order of amino acids in a protein chain, the protein hormones began to give ground. In 1956, for instance, Li and his group showed that the molecule of ACTH was made up of thirty-nine amino acids in a specific order and, furthermore, the en tire chain of the natural hormone was not essential to its action. Fragments consisting of little more than half the chain possessed major activity. That the chemical structure was significant was also shown by the fact that melanocyte-stimulating hormone (MSH), also obtained by Li from the pi tuitary, which produced some effects similar to those produced by ACTH, also possessed an amino acid chain, which in spots duplicated the order in ACTH. Li studied the growth hormone, per haps the most remarkable of the pitu itary hormones, for it controls the over all growth rate of the body, producing circus giants when present in excess, and midgets when present in inadequate quantities. Whereas ACTH from swine 8 4 6
[1383] ABELSON
CHANCE [1384] or cattle is effective on human beings, growth hormone from such creatures is not. Li isolated human growth hormone in 1956 and showed that its structure is quite different from other species tested. Its molecule is made up of 256 amino acids, so that it is far more complicated than the other pituitary hormones. How ever, it is quite likely that not all of this long chain is required for its activity. In 1970 Li synthesized human growth hor mone. [1383] ABELSON, Philip Hauge American physical chemist Bom: Tacoma, Washington, April 27, 1913 Abelson graduated from Washington State College in 1933 and obtained his Ph.D. at the University of California in 1939 under Lawrence [1241], While still a student, he had produced uranium fission but had not recognized the significance of what he had done at first. He was on the point of doing so when Hahn [1063] and Meitner [1060] man aged to forestall him. In 1940, when chemists were begin ning to concern themselves with the problem of separating uranium into its isotopes (since the rare isotope uranium- 235 was involved in the fission reaction), Abelson made an important suggestion. He pointed out that uranium hexa fluoride was a volatile liquid and its vapors were the easiest way of obtaining uranium atoms in the gaseous state. Those molecules of uranium hexafluoride that contain uranium-235 are almost 1 percent lighter than the molecules con taining the more common uranium-238. If part of the volume of gas is heated, the lighter molecules tend to concentrate in the hot region. By using this principle (thermal diffusion), samples of enriched uranium (containing more than the nor mal quantity of uranium-235) were pre pared. In 1940, also, Abelson assisted McMillan [1329] in initiating the study of the transuranium elements and in dis covering neptunium. In 1962 he became editor of Science and he was one of that substantial group of scientists who had serious reservations as to the expensive crash program car ried through the 1960s for placing a man on the moon. [1384] CHANCE, Britton American biophysicist Born: Wilkes-Barre, Pennsylvania, July 24, 1913 Chance was educated at the University of Pennsylvania, graduating in 1936 and obtaining his Ph.D. in 1940. He has since been on the faculty of the univer sity and has been a full professor of biophysics since 1949. Chance has tackled the problem of en zyme mechanisms. Nearly half a century earlier, Michaelis [1033] had evolved a theory to the effect that in the course of the action of an enzyme upon a substrate (that is, upon the compound or com pounds involved in the enzyme-catalyzed reaction) the enzyme and substrate form a more or less loosely bound combina tion, the enzyme-substrate complex. The discovery of this complex ex plained how the rate of enzyme- catalyzed reactions changed with certain alterations of the conditions of the reac tion. However, although most enzyme chemists accepted the existence of this complex, it remained a purely theoretical model, with no direct observational evi dence to testify as to its presence. In the 1940s Chance worked with peroxidase, an enzyme that catalyzed the oxidation of numerous organic com pounds by hydrogen peroxide. Perox idase has a heme group (a complex iron- containing compound best known for its occurrence in hemoglobin) as part of the molecule and this absorbs certain wave lengths of light strongly. The particular wavelengths absorbed shift with even small changes in the chemical nature of the molecule. When Chance added hydrogen perox ide to a solution of peroxidase, he could follow the changes in light absorption and noted that they came and went just as one would expect if an enzyme-sub strate complex was being formed, then
[1385] KAMEN
HODGKIN [1387] broken, in the manner predicted by Mi chaelis. In this way Chance deduced the mech anism of peroxidase action in minute de tail. The mystery was further stripped from the activity of enzymes, which was of greater interest to biochemists as the connection between enzymes and nucleic acids was becoming clear during the 1950s. [1385] KAMEN, Martin David Canadian-American biochemist Born: Toronto, Ontario, August 27, 1913 Kamen was educated in the United States, graduating from the University of Chicago in 1933 and going on for his Ph.D. in 1936. He became a naturalized American citizen in 1938. Kamen was interested in the isotopes of the light elements that were of partic ular interest to biochemists. Oxygen and nitrogen had no radioactive istopes long- lived enough to be useful and it was thought that the same held true for car bon. In 1940, however, Kamen isolated carbon-14, which turned out, surpris ingly, to have a half life of 5,700 years. It quickly became and remained the most useful of all isotopes in biochemical research and was even turned to histori cal and archaeological use by Libby [1342], Kamen had already worked with ox ygen-18, a stable but rare oxygen isotope in connection with photosynthesis. He showed that in the combination of car bon dioxide and water, in that funda mental light-catalyzed process the oxy gen that was liberated comes from the water molecule and not from carbon dioxide. With the discovery of carbon- 14, men such as Calvin [1361] could leap ahead in the further investigation of the details of photosynthesis. [1386] LOVELL, Sir Alfred Charles Bernard English astronomer Born: Oldland Common, Gloucestershire, August 31, 1913 Lovell, the son of a lay preacher, was educated at the University of Bristol, graduating in 1933 and obtaining his doctorate in 1936. He joined the faculty of Manchester University as a lecturer in physics at once. He was then interested in the ionosphere and worked on cosmic ray studies with Blackett [1207], During World War II he was occupied with radar research, and in 1946 he was one of those who showed that radar echoes could be obtained from daytime meteor showers, invisible to ordinary sight.
After the war he grew interested in radio astronomy. In 1951 he became the first professor of radio astronomy at Manchester University and began work toward the building of a giant, fully steerable radio telescope. The building of this 250-foot “big dish” at Jodrell Bank Experimental Station represented an epic effort in constuction that took six years. The turret rack of a battleship was, at Blackett’s suggestion, used to move the dish. It was finished (or nearly finished) just in time to track Sputnik I, a task that rescued him from the angry in quiries into the value of spending money for such an instrument. Since then the Jodrell Bank radio tele scope has been the most useful instru ment anywhere in the world for tracking satellites. Though it will inevitably be surpassed in the future, it will remain the first of the great radio telescopes to grow out of Reber’s [1368] homemade job. Lovell was knighted in 1961. [1387] HODGKIN, Alan Lloyd English physiologist Born: Banbury, Oxfordshire, Feb ruary 5, 1914 Educated at Cambridge, Hodgkin worked on radar during World War II, then joined the Cambridge faculty in 1945.
Hodgkin grew interested, in the late 1930s, in the mechanism of the nerve impulse. For the purpose of investi gation, he made use of the giant axon of the squid, a single nerve fiber that was,
[1388] DULBECCO
SPITZER [1390] on occasion, as much as a millimeter in diameter. He and his co-worker, A. F. Huxley [1419], were able to insert fine pipettes inside the axon, without damaging it, and thus test the ionic composition within and immediately outside the cell. By 1952 they had shown that the inte rior of the cell was rich in potassium ion and the exterior in sodium ion. At the moment when a nerve impulse passes, the situation changes. Sodium ion first floods into the cell and, a little while later, potassium ion moves out. Once the impulse has passed, sodium ion is pumped out of the cell, somehow, so that the fiber may be ready to carry an other impulse. For working out the importance of the “sodium pump,” Hodgkin and Huxley shared the 1963 Nobel Prize for physiol ogy and medicine with Eccles [1262]. (Hodgkin married the daughter of Rous [1067], who, two years later, also won a a Nobel Prize.) [1388] DULBECCO, Renato (dull-beck'o) Italian-American virologist
ary 22, 1914 Dulbecco earned his medical degree at the University of Turin in 1936. He went to the United States in 1947, be came an American citizen in 1953, and began teaching at the California Institute of Technology. He has also been as sociated with the Salk Institute and the University of California at San Diego Medical School. His most important work has been on cancer viruses and how they might possi bly bring about the chemical change within the cells that lead to cancer. Since the cell is such an enormously compli cated interplay of innumerable chemical reactions, Dulbecco introduced the tech nique of placing within the cell not in tact viruses but individual virus genes of known function in order to study the chemical changes that this produced. The promise of this technique earned him a share in the 1975 Nobel Prize for physiology and medicine. [1389] PERUTZ, Max Ferdinand Austrian-British biochemist
1914
Perutz was educated at the University of Vienna, but the gathering cloud of Nazism, just to the north in Hitler’s Ger many, and the deteriorating picture in Austria itself, caused him to leave for England in 1936. There he worked at Cambridge University, becoming inter ested in X-ray diffraction of proteins, with the aid and encouragement of W. L. Bragg [1141]. Perutz obtained his Ph.D. in 1940, but was interned as an enemy alien during World War II. After the war Perutz organized the laboratory of molecular biology at Cam bridge and took as his own problem the working out of the detailed structure of hemoglobin. In 1953 the break came. The heavier an atom the more efficiently it diffracts X rays. Perutz, therefore, added a single atom of a heavy metal like gold or mer cury to each molecule of protein and found he had altered the overall diffrac tion picture significantly. This now gave Perutz something to go on and eased the process of deduction from diffraction picture to atom position. Perutz assigned myoglobin to Kendrew [1415] and both produced the results of their research in 1960 and shared in the 1962 Nobel Prize in chemistry. [1390] SPITZER, Lyman, Jr. American astronomer and physi cist
Born: Toledo, Ohio, June 26, 1914
Spitzer graduated from Yale in 1935, then spent a year at Cambridge, En gland, under Eddington [1085], Return ing to the United States, he obtained a Ph.D. under H. N. Russell [1056] in 1938. He remained on the Yale faculty (except for work on undersea warfare during World War II) till 1947 when he 8 4 9
[1391] VONNEGUT
VAN ALLEN [1392] went to Princeton as head of the astron omy department. Spitzer was particularly interested in the formation of new stars out of the clouds of dust and gas in interstellar space under the influence of the weak magnetic fields that permeate its vast en vironment. The combination of high-temperature gas (“plasma”) and magnetic fields led him into research on fusion power. In order to force hydrogen gas to fuse into helium, liberating vastly more energy than even uranium fission does, the hy drogen must be raised to temperatures of 100 million degrees or so. To contain gas so ferociously hot, a merely material container will not do. Spitzer was one of the first to suggest that a magnetic field might be the an swer; and he devised a figure-eight shaped design (called a “stellarator”) for such a field. It has remained an impor tant tool in the continuing drive toward controlled hydrogen fusion. Spitzer was one of those scientists who early grew enthusiastic over the possi bility of rockets as a scientific tool. In 1947 he was already speculating on artificial satellites on which telescopes and other astronomic instruments might be mounted. [1391] VONNEGUT, Bernard American physicist
gust 29, 1914 Vonnegut (whose brother is the highly regarded science fiction novelist, Kurt Vonnegut) attended the Massachusetts Institute of Technology, graduating in 1936 and obtaining his Ph.D. in 1939. At M.I.T. he studied icing conditions, then joined the General Electric Re search Laboratories in 1945 to continue this work with Schaefer [1309], After dry ice was found effective as a cloud-seeder, Vonnegut took up the problem of finding some crystals that might serve in place of dry ice. He de cided that fine crystals of silver iodide were of the proper shape to serve as “seeds” and experiment proved him cor rect. Silver iodide replaced dry ice, for it had several advantages. It could keep indefinitely at room temperature, as dry ice could not. Furthermore, silver iodide crystals need not necessarily be liberated by plane. By taking advantage of up drafts they can be liberated on the ground and wafted upward into the cloud layers. (Dry ice would evaporate en route.) To be sure, silver iodide is rather an expensive chemical, but it has been estimated that two pounds would suffice to seed the clouds over the entire United States. In 1952 Vonnegut joined the staff of Arthur D. Little, Inc. [1392] VAN ALLEN, James Alfred American physicist
September 7, 1914 Van Allen, the son of an attorney, graduated from Iowa Wesleyan College (in his home town) in 1935. During his sophomore year there, he was already making measurements of cosmic ray in tensities. After graduation he attended the State University of Iowa, where he obtained his Ph.D. in 1939. Since 1951 he has been head of the physics depart ment at the State University of Iowa. During World War II, Van Allen, serving as a naval officer, developed the proximity fuze. This was a device that could be attached to an explosive weapon such as an antiaircraft shell. It emits radio waves that are reflected from the target. When the target is approached within a certain distance the reflected waves become intense enough to deto nate the explosive contained in the shell. In effect this meant that direct hits were not necessary and the effectiveness of an tiaircraft fire was multiplied many times. Even more important than the immedi ate wartime usefulness of the proximity fuze was the practice it gave Van Allen in miniaturization, since a great deal of electronic equipment had to be packed into a small space to make the fuze efficient. This was needed even more intensely after the war, for in Germany crucial 850
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