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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

Labelling of various macromolecules using positron emitting <sup>76</sup>Br and <sup>68</sup>Ga : Synthesis and characterisation

Yngve, Ulrika January 2001 (has links)
<p>Different prosthetic groups containing a trialkylstannyl- and an electrophilic group have been synthesised and labelled with the accelerator produced <sup>76</sup>Br (T<sub>1/2</sub>=16 h) through oxidative bromination. The labelled prosthetic groups were conjugated to amino-containing macromolecules such as proteins and 5´-modified oligonucleotides.</p><p><i>N</i>-Succinimidyl 4-[<sup>76</sup>Br]bromobenzoate <b>14 </b>was synthesised in 65 % radio-chemical yield and was conjugated to 5´-hexylamino-modified phosphodiester and phosphorothioate oligonucleotides in 12-19 % isolated radiochemical yield. The stability of the <sup>76</sup>Br-oligonucleotide-conjugates <i>in vivo</i> in rats was investigated. No degradation from the 5´-end, resulting in labelled, low molecular weight compounds was detected. Compound <b>14</b> has also been used for labelling of different proteins in 23-61% radiochemical yield.</p><p><i>N</i>-Succinimidyl-5-[<sup>76</sup>Br]bromo-3-pyridinecarboxylate <b>17</b> and methyl-4-[<sup>76</sup>Br]bromo-benzimidate <b>15 </b>were synthesised from the corresponding trimethylstannyl-compound in 25% and 40 % yield respectively. Compounds <b>14 </b>and <b>17</b> were conjugated to ε-Boc-octreotide in 55 and 50% isolated radiochemical yield respectively after microwave heating. Compound <b>15</b> did not react with octreotide under the conditions investigated. The two <sup>76</sup>Br-labelled octreotide derivatives showed different lipophilicity and different binding-properties to tissue from meningiomas.</p><p>Hyaluronic acid, a polysaccharide, was modified with tyramine and labelled by oxidative bromination using <sup>76</sup>Br in 10% radiochemical yield.</p><p>The generator produced <sup>68</sup>Ga (T<sub>1/2</sub>=68 min) was used to label octreotide and oligonucleotides modified with the metal chelating group 1,4,7,10-tetraazacyclo-dodecane-1,4,7,10-tetraacetic acid (DOTA). <sup>68</sup>Ga-DOTA-octreotide was isolated in 65% radiochemical yield and a phosphorothioated <sup>68</sup>Ga-DOTA-oligonucleotide was isolated in 35% radio-chemical yield after 30 min synthesis time.</p><p>Compound<b> 14 </b>was reacted with 3-aminomethylbenzylamine to give compound <b>18</b>. The specific radioactivity<b> </b>of<b> 18 </b>was determined to be 36 GBq/µmol by measuring the ratio between the mass-peaks for the <sup>76</sup>Br and <sup>79</sup>Br-compounds using packed-capillary LC-MS.</p>
2

Labelling of various macromolecules using positron emitting 76Br and 68Ga : Synthesis and characterisation

Yngve, Ulrika January 2001 (has links)
Different prosthetic groups containing a trialkylstannyl- and an electrophilic group have been synthesised and labelled with the accelerator produced 76Br (T1/2=16 h) through oxidative bromination. The labelled prosthetic groups were conjugated to amino-containing macromolecules such as proteins and 5´-modified oligonucleotides. N-Succinimidyl 4-[76Br]bromobenzoate <b>14 </b>was synthesised in 65 % radio-chemical yield and was conjugated to 5´-hexylamino-modified phosphodiester and phosphorothioate oligonucleotides in 12-19 % isolated radiochemical yield. The stability of the 76Br-oligonucleotide-conjugates in vivo in rats was investigated. No degradation from the 5´-end, resulting in labelled, low molecular weight compounds was detected. Compound <b>14</b> has also been used for labelling of different proteins in 23-61% radiochemical yield. N-Succinimidyl-5-[76Br]bromo-3-pyridinecarboxylate <b>17</b> and methyl-4-[76Br]bromo-benzimidate <b>15 </b>were synthesised from the corresponding trimethylstannyl-compound in 25% and 40 % yield respectively. Compounds <b>14 </b>and <b>17</b> were conjugated to ε-Boc-octreotide in 55 and 50% isolated radiochemical yield respectively after microwave heating. Compound <b>15</b> did not react with octreotide under the conditions investigated. The two 76Br-labelled octreotide derivatives showed different lipophilicity and different binding-properties to tissue from meningiomas. Hyaluronic acid, a polysaccharide, was modified with tyramine and labelled by oxidative bromination using 76Br in 10% radiochemical yield. The generator produced 68Ga (T1/2=68 min) was used to label octreotide and oligonucleotides modified with the metal chelating group 1,4,7,10-tetraazacyclo-dodecane-1,4,7,10-tetraacetic acid (DOTA). 68Ga-DOTA-octreotide was isolated in 65% radiochemical yield and a phosphorothioated 68Ga-DOTA-oligonucleotide was isolated in 35% radio-chemical yield after 30 min synthesis time. Compound<b> 14 </b>was reacted with 3-aminomethylbenzylamine to give compound <b>18</b>. The specific radioactivity<b> </b>of<b> 18 </b>was determined to be 36 GBq/µmol by measuring the ratio between the mass-peaks for the 76Br and 79Br-compounds using packed-capillary LC-MS.
3

Rekombinantinio žmogaus granulocitų kolonijas stimuliuojančio faktoriaus pasiskirstymas ir renatūracija vandens dvifazėse sistemose, dalyvaujant chelatuotiems metalų jonams / Partitioning and refolding of recombinant human granulocyte-colony stimulating factor in aqueous two-phase systems containing chelated metal ions

Zaveckas, Mindaugas 16 November 2005 (has links)
The contribution of Cys17 and surface-exposed histidine residues in rhG-CSF interaction with Cu(II), Ni(II) and Hg(II) ions chelated by Light Resistant Yellow 2KT-polyethylene glycol derivative was evaluated in aqueous two-phase systems composed of polyethylene glycol (PEG) and dextran. It was determined that His43, His52, His156 and His170 residues are involved in protein interaction with chelated Cu(II) ions. Protein interaction with chelated Ni(II) is governed by His52 and His170 residues, though Cys17 is also involved. The contribution of Cys17 side chain is dominant in the interaction between rhG-CSF and chelated Hg(II) ions. The direct interaction between chelated Hg(II) ions and the –SH group of protein was determined for the first time. Based on the study of the interaction between rhG-CSF and chelated metal ions, rhG-CSF was successfully refolded from inclusion bodies in aqueous two-phase systems PEG-dextran containing chelated Ni(II) or Hg(II) ions for the first time. The refolding of rhG-CSF (C17S) in these systems was more effective compared to that of intact rhG-CSF. The dependence of refolding efficiency of rhG-CSF (C17S) in two-phase systems containing chelated metal ions on the number of histidine mutations was evaluated. It was determined that the refolding efficiency of protein in the systems containing chelated Ni(II) is inversely proportional to the number of histidine mutations. The affinity of purified rhG-CSF (C17S) and its histidine mutants for... [to full text]
4

Možnosti odstranění zelených řas z betonových konstrukcí / The possibilities of green algae removal from concrete structures

Cochlárová, Milena January 2014 (has links)
This master´s thesis deals with the suppression of algal growth on concrete structures. The subject of the work is to design and coatings their own structural concretes containing protective element in order to inhibit the growth of algae. As the coating are tested commercially avaiable and newly created systems. Testing systems are based on the portland cement and chelates of metal (Cu, Ni, Co, Mn, Zn, Al).
5

Separation And Quantitation Of Some Platinum Group Metals By Rp-hplc

Alshana, Usama Ahmed 01 January 2005 (has links) (PDF)
In this study, a reversed-phase high performance liquid chromatography (RP-HPLC) method has been developed to separate and determine Pt and Pd after formation of their chelates with N,N-diethyl-N&#039 / -benzoylthiourea (DEBT). With the aim of reducing the number of steps in treating the samples, the method developed does not require the elimination of excess chelating reagent before the analysis of metal chelates. The different physical and chemical parameters affecting separation were examined in details. The whole analysis was completed on a C18 column in 16 min at 280 nm, with the mobile phase of acetonitrile-methanol-water (80:10:10, v:v:v) containing 0.20 mol l-1 pH 5.0 acetate buffer at a flow rate of 0.8 ml min-1. Detection limits of the method, based on 3s, were found as 14.2 ug l-1 for Pd and 0.77 mg l-1 for Pt using a 20-ul sample loop. Reproducibility of the method for ten repeated measurements was found as 2.36 % for 0.60 mg l-1 Pd and 2.58 % for 10.0 mg l-1 Pt as % RSD. The proposed method is a rapid, simple and highly selective method for the simultaneous determination of Pt and Pd by HPLC without the need for any interference elimination process.

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