Maine's heavy snows led turnpike maintenance personnel to bring "left-handed" snow plows into prominence. By using left-handed and traditional right-handed plows in tandem, they were able to distribute snow more evenly - an important advance that has been emulated by many highway maintenance crews across the country.
1999
YearAdded:
Image Credit: Courtesy Flickr/Doug Kerr (CC BY-SA 2.0)Era_date_from: 1947
1999
Steroid chemists often refer to the 1930s as the Decade of the Sex Hormones, when the molecular structures of certain sex hormones were determined and first introduced to medical practice as drugs. Russell Marker achieved the first practical synthesis of the pregnancy hormone, progesterone, by what now is known as the "Marker Degradation." Produced from starting material in a species of Mexican yam, Marker’s progesterone eventually became the preferred precursor in the industrial preparation of the anti-inflammatory drug cortisone.
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Era_date_from: 1938–1945
1999