Saturday, July 27, 2013
Blumberg's research dealt with polymorphisms in serum proteins of human blood. Polymorphisms are differences in proteins caused by different gene alleles. Alleles are different forms of the same gene. He took many trips to tropical countries to collect and study the blood proteins of people living there and studied how these differences affected the health of the their carriers. During his trips to Australia he found a unique protein in the blood of Australian aboriginal people, which he called Au. In 1966 he found a patient who had the Au protein spontaneously appear in their blood. The same patient developed hepatitis. From this result Blumberg determined that the Au protein was a surface protein for the hepatitis B virus. Using this result Blumberg and his team were able to develop a screening test and a vaccine for the Hepatitis B virus. For his discovery of the hepatitis B virus Blumberg shared the 1976 Nobel Prize in medicine with D. Carleton Gajdusek.
After winning the Nobel Prize Blumberg continued working to better understand the hepatitis B virus, including its affects on individuals carrying the virus. In 1994 Blumberg was elected fellow of the American Academy of Arts and Sciences and he served from 1999 to 2002 as the first director of the NASA Astrobiology Institute.
Blumberg died of an apparent heart attack on April 5, 2011, while he was attending a conference at NASA's Ames Research Center in Mountain View, California.
Blumberg, Baruch, Nobel Autobiography, at nobelprize.org
Rall, Glenn; Baruch S.Blumberg MD,1925-2011; Virology Blog at virology.ws
Baruch S. Blumberg Wikipedia Entry
Sunday, July 21, 2013
Brandt's research involved investigating metals. He coined the term semi-metals to describe elements that have both metal and non-metal characteristics. These elements are now called metalloids. Metaloids are the elements in the region between metal and non-metal elements on the periodic table (see here) In 1733 he investigated arsenic and its compounds. In 1735 he postulated that the blue color in an ore known as smalt was due to an unknown metal or semi-metal. In 1742 he was able to isolate this unknown blue metal which he named cobalt, taking the name from the old Teutonic word kobold meaning demon. Cobalt is atomic number 27 and is represented by the chemical symbol Co.
Brandt's later research involved using hot acid solutions to dissolve gold. Brandt's later publications dealt with criticism of the alchemical belief that other "base" metals could be transformed into gold. It has been said that he did more than any other chemist to clarify that transmutation of other metals into gold was impossible and that claims of alchemists that they could create gold from other metals were false.
Brandt died on April 29, 1768 in Stockholm, Sweden of prostate cancer.
Morris, Richard; The Last Sorcerers; Joseph Henry Press; 2003
"Brandt, Georg" in Complete Dictionary of Scientific Biography; Charles Scribner's Sons; 2008
Georg Brandt Wikipedia Entry
Sunday, July 14, 2013
During the 1820s Dumas developed a method of measuring the vapor densities of volatile liquids which he used to measure the atomic weights of 30 of the 59 the elements known at the time. Starting with the hypothesis of William Prout, that the atomic mass of hydrogen was 1 and all the other elements were multiples of hydrogen's mass, Dumas determined the masses of the other elements. Later Dumas began work on organic chemistry (chemistry involving compounds of carbon) going on to become one of the most advanced organic chemists of his time. In 1833 Dumas developed a method for determining the amount of nitrogen in an organic compound, founding modern analytical chemistry.
Dumas also studied physiological questions. In one of his first researches he determined that iodine was what was necessary factor to treat goiter. He also determined that kidneys removed urea, a form of nitrogen waste, from the blood.
When he reached middle age Dumas devoted more of his time to public service and less time to scientific research. He served as the minister of agriculture and commerce and as director of the mint. He was also served as a senator.
Dumas died on April 10, 1884 in Cannes. He was buried in Paris and his is one of the 72 names memorialized on the Eiffel Tower.
Anon; Obituary; Proceedings of the Royal Society; (1884) 37:X
Cooke, Josiah Parsons; "Jean-Baptiste-Andre Dumas"
Newbold, Brian; "Jean-Baptiste-Andre Dumas: A Dominating Influence in Nineteenth Century French Chemistry";
Jean-Baptiste Dumas Wikipedia Entry
Monday, July 8, 2013
Stevens research while at Bryn Mawr was studying the chromosomes of sex cells of meal worms. Sex cells are the cells produced by males and females that give rise to progeny. These cells have half the number of chromosomes that normal cells do. When male and female sex cells combine, a process called fertilization, it gives rise to a single cell with half of its chromosomes from the father and half from the mother that will eventually develop into progeny. Stevens noted in her research that some male sex cells have a chromosome not found in female sex cells. She proposed that this extra chromosome was responsible for determining the sex of the offspring. Today we call this extra chromosome the Y-chromosome and when a male sex cell, with a Y-chromosome, fertilizes an egg the offspring will be male. Half of male sex cells have an X-chromosome and when it fertilizes a female sex cell the offspring will be female. At the time it was believed that the gender of offspring was determined by the mother and environmental factors and Stevens' research was not widely accepted. Today we know that the sex cells of the father, with either Y or X chromosomes, determine the gender of the offspring through the mechanism discovered by Stevens.
Stevens died of breast cancer on May 4, 1912 at the early age of 39.
DNA Learning Center; "Nettie Maria Stevens (1861-1912)"; Retrieved from: dnaftb.org
Scitable; "Nettie Stevens: A Discoverer of Sex Chromosomes"; Retrieved from: nature.com
Nettie Stevens Wikipedia Entry
Monday, July 1, 2013
Henderson's initial research interest upon returning to America was in understanding buffer systems and how the human body maintains its pH balance. In the blood carbon dioxide from cellular respiration combines with water to form carbonic acid. Carbonic acid (H2CO3) exists in the blood primarily in the form of bicarbonate (HCO3-). Bicarbonate and the proteins of the blood act as buffers that maintain the body's pH. When excess acid or base is produced bicarbonate acts to maintain the body's pH at a slightly basic pH (about 7.35). From his research on buffers Henderson developed an equation that can be used to calculate the pH of a buffer system. The Henderson/Hasselbalch equation equates the pH to the pKa of the acid in the buffer plus the log of the concentration of the acid's anion divided by the concentration of the associated acid (pH = pKa + log([A-]/[HA]).
Henderson's later research career dealt with more philosophical issues in science. He published two books, The Fitness of the Environment and The Order of Nature, devoted to the discussion of global problems of the fitness of organisms in their environments. In The Order of Nature he concluded that "the whole evolutionary process, both cosmic and organic, is one, and the biologist may rightly regard the universe, in its essence as biocentric."
Henderson died on February 10, 1942 in Cambridge, Massachusetts.
Cannon, Walter M.; "Biographical Memoir of Lawerence Joseph Henderson 1878-1943"; National Academy Press; 1943
Mayer, Jean; "Lawrence J. Henderson - A Biographical Sketch"; The Journal of Nutrition (1968)94:3-5
Smith, Charles H.; "Henderson, Lawrence Joseph (United States 1878-1942)"; retrieved from: http: wku/people.wku.edu/charles.smith
Lawerence Joseph Henderson Wikipedia Entry