pKa values of aqua ligands of platinum (II) anticancer complexes: [1H, 15N] and 195Pt NMR Studies of cis- and trans- [PtCl2 (NH3) (Cyclohexylamine)]

Syntheses and NMR studies are reported of two 15N-labelled Pt(II) complexes of anticancer interest: cis-PtCl2(15NH3)(c-C6H1115NH2), a metabolite of the orally-active Pt(IV) complex cis,trans,cis-[PtCl2(acetate)2(c-C6H11NH2)(NH3), and trans-[PtCl2(15NH3)(c-C6H1115NH2), a reduction product of the active Pt(IV) complex trans,trans,trans-[PtCl2(OH)2(c-C6H11NH2). For cis-[PtCl2(15NH3)(c-C6H1115NH2), hydrolysis was faster for the chloride ligand trans to cyclohexylamine, and the pKa values determined by [1H, 15N NMR spectroscopy for the two cis monoaqua isomers were the same (6.73). The trans monoaqua complex was a stronger acid with pKa of 5.4 (determined by 195Pt NMR). For the cis diaqua complex, pKa values of 5.68 and 7.68 were determined.

Case based adaptation using interpolation over nominal values

In this paper we propose a method for interpolation over a set of retrieved cases in the adaptation phase of the case-based reasoning cycle. The method has two advantages over traditional systems: the first is that it can predict “new” instances, not yet present in the case base; the second is that it can predict solutions not present in the retrieval set. The method is a generalisation of Shepard’s Interpolation method, formulated as the minimisation of an error function defined in terms of distance metrics in the solution and problem spaces. We term the retrieval algorithm the Generalised Shepard Nearest Neighbour (GSNN) method. A novel aspect of GSNN is that it provides a general method for interpolation over nominal solution domains. The method is illustrated in the paper with reference to the Irises classification problem. It is evaluated with reference to a simulated nominal value test problem, and to a benchmark case base from the travel domain. The algorithm is shown to out-perform conventional nearest neighbour methods on these problems. Finally, GSNN is shown to improve in efficiency when used in conjunction with a diverse retrieval algorithm.

Enlightenment and mission in early nineteenth century South Africa

In the early 19th century the London Missionary Society’s activities in South Africa were the subject of great scandal and a source of disrepute. The behaviour and attitudes of the first wave of LMS missionaries had challenged, and caused outrage, to both the political and moral norms of the colony. The radical attitudes and unconventional private lives of many of the early missionaries had also clearly shocked the Directors in Europe. In these controversies, and in the manner that the Society dealt with them, there can be read a contestation about not only the character, but also the purpose of mission activity. Was the Missionary task to work for political stability, to spread European values and help prepare a compliant and educated workforce? Or was it to save ‘lost souls’ and turn people away from idolatry and sin? Or, again, was it to fight for the oppressed, to liberate slaves and oppose tyranny? These debates were framed in complex and contradictory ways by a larger discussion that was informed by the new ideas and agendas that had emerged in the 18th century, commonly referred to as ‘The Enlightenment’. This paper traces the contours of an engagement between ‘Evangelical’ values and ‘Enlightenment’ principles through an exploration of the issues of the day such as: abolitionism, women’s rights, civilization and savagery. [From the Author]