Groups discovery

The Lawrence Berkeley Laboratory and other groups were unable to confirm the spontaneous-fission reaction of Ku-260, so the Dubna groups discovery was disputed. The Berkeley equipment was unable to accelerate neon ions to the speeds required to produce Ku-260, and thus they tried a different reaction in a new automated rapid chemistry apparatus that identified and confirmed new isotopes of heavy metals. The procedure involved bombarding the element californium-239 with a mixture of the isotopes carbon-12 and carbon-13 ions, as follows ... 

The claims for discovery and the naming of Element 104 are still in question. The Berkeley group proposes for the new element the name rutherfordium (symbol Rf), in honor of Ernest R. Rutherford, a New Zealand physicist. Meanwhile, the International Union of Pure and Applied Physics has proposed using the neutral temporary name, unnilquadium. 

In June 1974, members of the Joint Institute for Nuclear Research in Dubna, U.S.S.R., reported their discovery of Element 106, which they reported to have synthesized. Glenn Seaborg was part of this group, and the element was named in his honor. Seaborgium is often still referred to as Element 106 because the international committee in charge of names changed the rules. They decided retroactively it couldn t be named after a living person. 

Other experiments were made to aid in confirmation of the discovery. Neither the Dubna team nor the Berkeley-Eivermore Group has proposed a name as of yet for element 106 (unnilhexium). 

The isotope produced was the 20-hour 255Fm. During 1953 and early 1954, while discovery of elements 99 and 100 was withheld from publication for security reasons, a group from the Nobel Institute of Physics in Stockholm bombarded 238U with 160 ions, and isolated a 30-min alpha-emitter, which they ascribed to 250-100, without claiming discovery of the element. This isotope has since been identified positively, and the 30-min half-life confirmed. 

Breslow immediately grasped the significance of his observation. He interpreted this discovery in terms of a hydrophobic effect Since in the Diels-Alder reaction. .. the transition state. .. brings together two nonpolar groups, one might expect that in water this reaction could be accelerated by hydrophobic interactions ". ... 

Molecules with icosahedral symmetry are not new but the discovery of the newest of them, Ceo or buckminsterfiillerene, has had such a profound effect on chemistry in recent years that 1 thought it useful fo include a discussion of fhe icosahedral poinf group fo which Ceo belongs. 

Deficiency Diseases. Not only did cereals make an important contribution to improving the general status of humankind, but they also were important dietary components of some groups of people who showed certain nutritional deficiencies. This observation led to the discovery of some of the vitamins. These deficiency diseases have been most prominently associated with use of rice, com, and wheat. 

As indicated in Figure 4, the early transactinide elements find their place back in the main body of the Periodic Table. The discoverers of the currendy known transactinide elements, suggested names and symbols, and dates of discovery are Hsted in Table 10 (19). Because there are competing claims for the discovery of these elements, the two groups of discoverers in each case have suggested names for elements 104 and 105. In the case of elements 106—109, names for the elements have not been suggested in order to avoid another dupHcation. 

The discovery of new broad spectmm antibiotics has been accompanied by the development of processes for fluorinated feedstocks ring-fluorinated aromatics for those quinolones containing a fluorobenzopyridone group, and fluorinated pyridine precursors for those antibiotics containing a naphthyridine nucleus (enoxacin, tosufloxacin) (see Table 14). 

The discovery in 1900 of the existence of blood groups, together with improved understanding of the importance of sterile conditions, paved the way to modem blood transfusion therapy. In 1915, the feasibiUty of storage of whole blood was demonstrated. During World War I, the optimal concentration of citrate for use as an anticoagulant was determined. This anticoagulant was used until 1942, when the acid—citrate—dextrose (ACD) solution was developed. 

Historically, the discovery of one effective herbicide has led quickly to the preparation and screening of a family of imitative chemicals (3). Herbicide developers have traditionally used combinations of experience, art-based approaches, and intuitive appHcations of classical stmcture—activity relationships to imitate, increase, or make more selective the activity of the parent compound. This trial-and-error process depends on the costs and availabiUties of appropriate starting materials, ease of synthesis of usually inactive intermediates, and alterations of parent compound chemical properties by stepwise addition of substituents that have been effective in the development of other pesticides, eg, halogens or substituted amino groups. The reason a particular imitative compound works is seldom understood, and other pesticidal appHcations are not readily predictable. Novices in this traditional, quite random, process requite several years of training and experience in order to function productively. 

The name naphthenic acid is derived from the early discovery of monobasic carboxyUc acids in petroleum, with these acids being based on a saturated single-ring stmcture. The low molecular weight naphthenic acids contain alkylated cyclopentane carboxyUc acids, with smaller amounts of cyclohexane derivatives occurring. The carboxyl group is usually attached to a side chain rather than direcdy attached to the cycloalkane. The simplest naphthenic acid is cyclopentane acetic acid [1123-00-8] (1, n = 1). 

The discovery that vitamin D metaboUtes play a much larger biochemical role than just maintaining calcium homeostasis has stimulated a number of groups around the world to develop more economical chemical syntheses for the vitamin D metaboUtes and analogues, which might be useful ki studykig and treating D -related diseases and conditions. Many of these methods are reviewed ki References 139 and 140. 

Since the discovery of SQ 83,360, compounds such as U-78,608 [123444-35-9] (64) having different linker groups between the hydroxypytidone group and the sulfonyl residue have been reported. U-78,608 and SQ 83,360 have similar in vitro and in vivo activity (45). 

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