http://vital.seals.ac.za:8080/vital/access/manager/Index ${session.getAttribute("locale")} 5 http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4288 Wed 12 May 2021 23:05:00 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4286 Wed 12 May 2021 22:28:40 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4557 Wed 12 May 2021 20:17:39 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4285 Wed 12 May 2021 19:56:19 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4280 Wed 12 May 2021 19:10:00 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4562 Co(II) > Ni(II). The Schiff-base derivatives were prepared from the ligands and para-methoxysalicylaldehyde and their Cu(II) complexes were synthesized in order to determine their biological activity. The Schiff-base ligands were found to be less active than their parent ligands. The Cu(II) complexes are not soluble in water, DMSO or DMF, as a result and could not be evaluated for their biological activity. Based on the good results from the antimicrobial evaluation, the antiplasmodial activity of some of the Co(II), Ni(II) and Cu(II) complexes of the thiomethylated ligands against Plasmodium falciparum (FCR-3) was determined. At 50 μM concentration level, the Cu(II) complexes show activity equal or better than the prophylactic chloroquine. The Cu(II) complexes with the methoxy-substituted demonstrated exceptional activity but their Co(II) and Ni(II) analogues did not show any activity. The cytotoxicity of the active Cu(II) complexes at 50 μM concentration was determined against the breast cancer cell line (MDA-MB-231). The compounds destroyed the cancer cell in the range of 28–40%, thus showing their preferred activity against the parasitic cell instead of the cancer cell. The selectivity demonstrated by these compounds have shown them to be potential antimalarial agents and this could be further investigated.]]> Wed 12 May 2021 17:24:20 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4293 Wed 12 May 2021 17:24:17 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4284 Wed 12 May 2021 17:16:34 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4283 Wed 12 May 2021 17:16:26 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4451 Wed 12 May 2021 16:46:13 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4281 Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.]]> Wed 12 May 2021 16:26:16 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4276 Wed 12 May 2021 16:06:38 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4439 Wed 12 May 2021 15:44:41 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4287 0.99. In the column experiment the highest loading capacity of Pt and Pd were 7.4 mg/g and 4.3 mg/g respectively on the nanofiber sorbent material based on ethylenediamine (EDA). The polystyrene and silica-based resins with triethylenetetramine (TETA) functionality (M-TETA and S-TETA) showed selectivity for platinum and palladium, respectively. Metal chlorido complexes loaded on the sorbent materials were recovered by using 3% m/v thiourea solution as teh eluting agent with quantitative desorption efficiency under the selected experimental conditions. The separation of platinum from palladium was partially achieved by selective stripping of PtCl₆²⁻ with 0.5 M of NaClO₄ in 1.0 M HCI with PdCl₄²⁻ was eluted with 0.5 M thiourea in 1.0 M HCI. The selectivity of the M-TETA and S-TETA sorbent materials was proved by column separation of platinum(IV) and palladium(II), respectively, from synthetic solutions containing iridium(IV) and rhodium(III). The loading capacity for platinum on M-TETA was 0.09 mg/g while it was 0.27 mg/g for palladium on S-TETA.]]> Thu 13 May 2021 07:36:09 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4278 Thu 13 May 2021 07:14:17 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4533 Thu 13 May 2021 06:26:02 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4555 Thu 13 May 2021 05:23:51 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4277 Thu 13 May 2021 03:57:19 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4450 Thu 13 May 2021 03:23:18 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4291 Thu 13 May 2021 01:46:25 SAST ]]> http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4282 Thu 13 May 2021 00:27:23 SAST ]]>