https://commons.ru.ac.za/vital/access/manager/Index en-us 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:2403 Wed 12 Oct 2022 12:47:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5254 Wed 12 May 2021 23:02:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4941 Wed 12 May 2021 22:54:13 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4984 Wed 12 May 2021 22:36:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4155 Wed 12 May 2021 20:51:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5266 Wed 12 May 2021 20:24:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1440 Wed 12 May 2021 20:20:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:39813 Wed 12 May 2021 20:19:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3034 Wed 12 May 2021 20:17:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3478 Wed 12 May 2021 20:12:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4936 Wed 12 May 2021 19:51:30 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4846 Wed 12 May 2021 19:46:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:39835 Wed 12 May 2021 19:42:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4658 Wed 12 May 2021 19:32:22 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:33221 Wed 12 May 2021 19:13:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6026 Wed 12 May 2021 18:46:19 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6179 Wed 12 May 2021 18:21:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:39834 Wed 12 May 2021 18:16:56 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3802 Wed 12 May 2021 17:47:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6181 Wed 12 May 2021 17:32:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2783 Wed 12 May 2021 17:23:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3465 Wed 12 May 2021 17:14:16 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3756 trifluoperazine> perphenazine > rochlorperazine. In order to assess their photostability an HPLC method was developed and validated for linearity, accuracy and precision, selectivity, limit of detection and quantitation and ruggedness. Preliminary solution photostudies under controlled light conditions (UV, sunlight, fluorescent light) indicated that the rate of degradation followed first-order kinetics with perphenazine the most susceptible to.photodegradation under all light conditions studied. In vitro and in vivo metabolism yielding the 5-sulphoxide and its reported presence on decomposition of the phenothiazines25 led to the development of a synthetic procedure suitable for the sutphoxides of all four derivatives based on the method proposed by Owens et al. in order to provide standards for comparison in the photostudies⁷. Since ICH regulations require that impurities> 0.1 % are examined and identified⁷⁴ and semi-preparative isolation of photoproducts proved unsuccessful, LC-MS having been well documented for structural.elucidation⁷⁵ ⁷⁵ ⁷⁶ ⁷⁷ was used to characterize solution (UV, sunlight, fluorescent light) and preliminary solid (UV) photostudies. The chloroderivatives underwent dechlorination and sulphoxidation with subsequent photosubstitution in the case of prochlorperazine to yield the 2-hydroxy derivative and sulphoxidation of the dechloro-derivative of perphenazine. The sulphoxides of both trifluoperazine and fluphenazine were formed with further oxidation to the respective sulphones occurring. Preliminary solid state (UV) photostudies showed fluphenazine to be the least stable with 30.71 % degradation as opposed to 7.57% for prochlorperazine, 4.28% for perphenazine and 7.10% for trifluoperazine witn sulphoxidation observed to be. the major degradation pathway. Since in vitro metabolism of perazine derivatives is reported to occur via N-oxidation, N-demethylation, sulphoxidation and aromatic hydroxylation¹⁸ it does appear that there is some correlation between metabolic and photoproducts. However the fact that solution (UV) photostudies indicates trifluoperazine to be the most and perphenazine the least stable does not concur with the proposed order of pharmacological activity.]]> Wed 12 May 2021 16:36:16 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4036 Wed 12 May 2021 16:13:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3761 Wed 12 May 2021 15:53:48 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1512 Wed 12 May 2021 15:50:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5252 Wed 12 May 2021 15:44:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42661 Wed 12 May 2021 14:36:53 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42156 Wed 12 May 2021 14:12:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42960 Wed 12 May 2021 13:56:12 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:38197 Wed 08 May 2024 19:22:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:74571 Tue 30 Jul 2024 11:04:30 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2350 Tue 27 Aug 2024 08:49:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6356 0.95) was noted for both methods of assessment. The chromameter ED[subscript 50] values determined in this study were approximately 2 hours for both preparations. At this dose duration the instrument would not be sensitive enough to distinguish between weak blanching responses and normal skin for bioequivalence assessment purposes.]]> Tue 14 May 2024 10:45:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:54490 Tue 14 May 2024 10:23:45 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:37711 Tue 14 May 2024 10:06:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1939 Tue 13 Aug 2024 08:44:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:74729 Tue 06 Aug 2024 12:58:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57084 Thu 29 Sep 2022 22:30:33 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57081 Thu 29 Sep 2022 22:21:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57073 5 μg ml−1) are determined by adsorptive cathodic stripping voltammetry (AdCSV) on a mercury film glassy carbon electrode, using catechol, 4-methylcatechol, 4-t-butylcatechol and resorcinol as complexing ligands. Complexes of lead, copper and bismuth with resorcinol showed the largest increase in current with increase in metal concentration, whereas complexes of these metals with 4-t-butylcatechol showed the lowest current response. Cadmium showed a different behaviour from the other three metals in that the highest current response was observed with 4-methylcatechol. The four metals could be determined simultaneously in the presence of resorcinol, although considerable interference was observed between bismuth and copper.]]> Thu 29 Sep 2022 19:45:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57072 Thu 29 Sep 2022 19:40:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3146 Thu 29 Aug 2024 09:51:31 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:73490 Thu 20 Jun 2024 08:41:18 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:538 Thu 16 May 2024 06:38:34 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:7135 Thu 15 Jul 2021 21:37:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:7134 Thu 15 Jul 2021 21:37:34 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3682 Thu 13 May 2021 15:06:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2718 Thu 13 May 2021 12:02:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4307 Thu 13 May 2021 08:49:15 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5736 Thu 13 May 2021 08:19:42 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4844 Thu 13 May 2021 08:12:15 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1301 Thu 13 May 2021 08:07:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29303 Thu 13 May 2021 08:05:37 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5478 Thu 13 May 2021 07:39:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4847 Thu 13 May 2021 07:25:44 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2421 Thu 13 May 2021 07:02:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4662 Thu 13 May 2021 06:54:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4020 Thu 13 May 2021 06:21:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29768 Thu 13 May 2021 05:44:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5727 Thu 13 May 2021 05:33:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1517 Thu 13 May 2021 05:27:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4425 Thu 13 May 2021 05:19:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2768 Thu 13 May 2021 05:15:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:890 Thu 13 May 2021 05:12:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:668 Thu 13 May 2021 04:55:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:37769 Thu 13 May 2021 04:54:37 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34625 Thu 13 May 2021 04:50:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5292 Thu 13 May 2021 04:43:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5409 Thu 13 May 2021 04:37:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5293 Thu 13 May 2021 03:51:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3156 Thu 13 May 2021 03:38:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5692 Thu 13 May 2021 03:16:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2425 Thu 13 May 2021 03:13:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4015 chitin> glucan > intact cell walls exists. However, these components differ in their affinities for metal ions. Storage of metal ions within the cell occurs predominantly in the vacuole. The present study concluded that metal accumulation by the vacuole could be related to size. Metal accumulation occurred in the order of Cu2+ > Co2+ > Cd2+ with a corresponding decrease in atomic radii of Cd2+ > C02+ > Cu2+. Vacuolar ion deposition occurs at an early stage during the internalization of metal ions within the yeast cells. At the onset of vacuolar saturation, depositions of metal ions as granules within the cytosol occurs. In the presence of heavy metal cations viable yeast cells can be shown to exhibit two types of cellular responses. Uptake of Cu2+ and Cd2+ causes the loss of intracellular physiological cations from within the yeast cell. In comparison, uptake of Co2+ into the cell does not have this effect. All three heavy metal cations initiate plasma cell membrane permeability, thus the Cu2+ and Cd2+ induced loss of the intracellular cations, occurs. ~ a result of ion-exchange mechanisms and not due to cation leakage brought about by membrane permeabilization. Uptake of heavy metals by viable yeasts appears to be generally non-selective though the amount of metals accumulated are largely affected by the ratio of ambient metal concentration to biomass quantity. In addition, the energy dependent nature of internalization necessitates the availability of an external energy source for metal uptake by viable yeast cells. For these reasons metal removal from industrial waste water was investigated using non-viable biomass. By immobilizing the yeast cells additional mechanical integrity and stability was conferred apon the biomass. The three types of biomass preparations developed in this study, viz. polyvinyl alcohol (PV A) Na-alginate, PV A Na-orthophosphate and alkali treated polyethylenimine (PEI):glutaraldehyde (GA) biomass pellets, all fulfilled the necessary physical requirements. However, the superior metal accumulating properties of the PEI:GA biomass determined its selection as a biosorbent for bioremediation purposes. Biosorption of heavy metals by PEI:GA biomass is of a competitive nature, with the amount of metal accumulated influenced by the availability of the metal ions. This availability is largely determined by the solution pH. At low pH values the affinity of the biomass for metals decreases, whilst enhanced metal biosorption occurs at higher pHs, ego pH 4.5 - 6.0. PEI:GA biomass pellets can be implemented -as a biosorbent for the bi9remediaiton of high concentration, low-volume metal containing industrial waste. Several options regarding the bioremediation system are available. Depending on the concentration of the metals in the effluent, the bioremediation process can either be used independently or as part of a biphasic remediation system for the treatment of waste water. Initial phase chemical modification may be required, whilst two types of biological systems can be implemented as 'part of the second phase. The PEI:GA biomass can either be contained within continuous-flow fixed bed tanks or continuous-flow stirred bioreactor tanks. Due to the simplicity of the process and the ease with which scale-up is facilitated, the second type of system shows greater application potential for the treatment of this type of industrial waste water than the fixed-bed systems.]]> Thu 13 May 2021 02:58:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1690 Thu 13 May 2021 02:48:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5654 Thu 13 May 2021 02:32:42 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1436 Thu 13 May 2021 02:32:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29767 Thu 13 May 2021 01:55:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:15031 Thu 13 May 2021 01:50:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:39855 Thu 13 May 2021 01:44:18 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4226 Thu 13 May 2021 01:32:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5265 Thu 13 May 2021 01:13:19 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3765 Thu 13 May 2021 00:59:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4943 Thu 13 May 2021 00:25:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4018 Thu 13 May 2021 00:24:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5691 Thu 13 May 2021 00:02:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3004 Thu 11 Jul 2024 15:19:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6506 Thu 11 Aug 2022 07:09:04 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:35452 Thu 11 Aug 2022 06:39:06 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2987 Mon 26 Aug 2024 16:22:13 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:75093 Mon 19 Aug 2024 11:44:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:75091 Mon 19 Aug 2024 11:30:15 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:35782 Mon 13 May 2024 15:06:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6675 Mon 13 May 2024 09:49:28 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4657 Mon 06 May 2024 09:03:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:694 Fri 30 Aug 2024 05:28:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1697 Fri 30 Aug 2024 04:32:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:75047 Fri 16 Aug 2024 09:32:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:74675 Fri 02 Aug 2024 15:38:30 SAST ]]>