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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ring a modification of miltirone: synthesis of nitrogen containing compounds.

January 1990 (has links)
by Yee-kwan Lau. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 65-67. / Chapter I. --- Acknowledgements --- p.1 / Chapter II. --- List of Nomenclature --- p.2 / Chapter III. --- Abstract --- p.10 / Chapter IV. --- Introduction --- p.11 / Chapter V. --- Results and Discussion: / Chapter i. --- Synthesis of ortho-quinonoid compounds related to miltirone ( / ) --- p.17 / Chapter ii. --- Pharmacological profile of synthetic compounds --- p.37 / Chapter VI. --- Conclusion --- p.33 / Chapter VII. --- Experimental Section --- p.39 / Chapter VIII. --- References and Notes --- p.55 / Chapter IX. --- Spectra --- p.68
2

The photochemistry of unsaturated nitrogen compounds

Spencer, George Lynton. January 1973 (has links) (PDF)
No description available.
3

Engineering homoaromatic substrate specificity into aliphatic-specific Geobacillus pallidus RAPc8 nitrile hydratase

Parikshant Kowlessur January 2007 (has links)
<p>Geobacillus pallidus RAPc8 is a thermophilic nitrile-degrading isolate, obtained from thermal sediment samples of a New Zealand hot spring. The G. pallidus RAPc8 NHase gene has been cloned and expressed in E. coli. The recombinant NHase exhibits nitrile-degrading activity at 50 &deg / C, capable of degrading branched, linear and cyclic heteroaromatic nitrile substrates. However, no activity was found on homoaromatic nitrile substrates such as benzonitrile. In the present study, high levels of activity on benzonitrile were detected with a double mutant &beta / F52G&beta / F55L. Kinetic analysis on the mutant enzyme showed an 8-fold decrease in KM with benzonitrile (0.3mM) compared to acrylonitrile (2.6mM). Specificity constants (kcat/KM) of 5900 and 450 s-1.mM-1 were obtained for the double mutant on benzonitrile and acrylonitrile respectively. The amino acid residues lining the substrate channel were identified and the geometric dimensions measured. Cavity calculations revealed a 29% increase in volume and a 13% increase in inner surface area for the substrate channel of the double mutant when compared to the wild type. Surface representation of the wild type structure revealed two extended, curved channels, which are accessible to the bulk solvent from two locations in the heterodimer. The removal of the &beta / F52 may have contributed to the presence of a single channel with two opposing openings across the dimers with no internal blockage. Normal Mode Analysis calculations also indicate a higher intrinsic flexibility of the mutant relative tothe wild type enzyme. The increased flexibility within the mutant NHase could have introduced a functionally relevant aromatic substrate recognition conformation</p>
4

Screening for subtate tolerant Geobacillus pallidus RAPc8 nitrile hydratase

Mketsu, Moses Clive Masisange January 2009 (has links)
<p>In this study G. pallidus RAPc8 NHase mutants were screened for reduced substrate inhibition compared to the wild type enzyme. Wild type and mutant enzymes were expressed and purified using hydrophobic interaction chromatography. Amidase coupled enzyme stop assays were conducted using 3-cyanopyridine as a substrate, whereas continuous enzyme kinetics were conducted using acrylonitrile as a substrate.</p>
5

New approaches to nitrogen ligands bearing electron withdrawing groups and their role in coordination chemistry

Shukla, Piyush, 1977- 27 July 2011 (has links)
Not available / text
6

Screening for subtate tolerant Geobacillus pallidus RAPc8 nitrile hydratase

Mketsu, Moses Clive Masisange January 2009 (has links)
<p>In this study G. pallidus RAPc8 NHase mutants were screened for reduced substrate inhibition compared to the wild type enzyme. Wild type and mutant enzymes were expressed and purified using hydrophobic interaction chromatography. Amidase coupled enzyme stop assays were conducted using 3-cyanopyridine as a substrate, whereas continuous enzyme kinetics were conducted using acrylonitrile as a substrate.</p>
7

Engineering homoaromatic substrate specificity into aliphatic-specific Geobacillus pallidus RAPc8 nitrile hydratase

Parikshant Kowlessur January 2007 (has links)
<p>Geobacillus pallidus RAPc8 is a thermophilic nitrile-degrading isolate, obtained from thermal sediment samples of a New Zealand hot spring. The G. pallidus RAPc8 NHase gene has been cloned and expressed in E. coli. The recombinant NHase exhibits nitrile-degrading activity at 50 &deg / C, capable of degrading branched, linear and cyclic heteroaromatic nitrile substrates. However, no activity was found on homoaromatic nitrile substrates such as benzonitrile. In the present study, high levels of activity on benzonitrile were detected with a double mutant &beta / F52G&beta / F55L. Kinetic analysis on the mutant enzyme showed an 8-fold decrease in KM with benzonitrile (0.3mM) compared to acrylonitrile (2.6mM). Specificity constants (kcat/KM) of 5900 and 450 s-1.mM-1 were obtained for the double mutant on benzonitrile and acrylonitrile respectively. The amino acid residues lining the substrate channel were identified and the geometric dimensions measured. Cavity calculations revealed a 29% increase in volume and a 13% increase in inner surface area for the substrate channel of the double mutant when compared to the wild type. Surface representation of the wild type structure revealed two extended, curved channels, which are accessible to the bulk solvent from two locations in the heterodimer. The removal of the &beta / F52 may have contributed to the presence of a single channel with two opposing openings across the dimers with no internal blockage. Normal Mode Analysis calculations also indicate a higher intrinsic flexibility of the mutant relative tothe wild type enzyme. The increased flexibility within the mutant NHase could have introduced a functionally relevant aromatic substrate recognition conformation</p>
8

The reaction of nitrous oxide with the aquopenta-ammineruthenium (II) ion : characterisation of penta-ammine (dinitrogen oxide)-ruthenium (II) complexes

Sparrow, Graham Jeffrey January 1972 (has links)
vii, 276 leaves : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1973) from the Dept. of Physical and Inorganic Chemistry, University of Adelaide
9

The photochemistry of unsaturated nitrogen compounds

Spencer, George Lynton January 1973 (has links)
193 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1975
10

The reaction of nitrous oxide with the aquopenta-ammineruthenium (II) ion : characterisation of penta-ammine (dinitrogen oxide)-ruthenium (II) complexes

Sparrow, Graham Jeffrey January 1972 (has links)
vii, 276 leaves : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1973) from the Dept. of Physical and Inorganic Chemistry, University of Adelaide

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