48 research outputs found
Synthesis, Structure of Nitrogen-Containing Phosphinogold(I) Ferrocenes. In vitro Activity against Bladder and Colon Carcinoma Cell Lines
The gold salt [(tht)AuCl] was reacted with [1-N,N-dimethylaminométhyl-2-diphenylphosphino]ferrocene (1) forming the bimetallic derivative 4. The reaction of methyl iodide
and tetramethylammonium bromide on the chloride 4 produced the ammonium salt 5 and the
bromide 6 respectively. New aminophosphines 2 and 3, which represent two of the rare
phosphorylated metallocenes containing P(III)-N bond have also been coordinated to gold(I) to
form 7 and 8. The presence of the ethoxy group in 7 provides evidence for the lability of one
nitrogen-phosphorus bond. The X-ray structure of compounds 4 and 7 have been established.
Both crystallize in space group P21/c, monoclinic, with a = 11.095(2) Ă
, b = 12.030(3) Ă
, c =
17.763(4) Ă
, ÎČ= 94.02(2)â, Z = 4 for 4 and a = 14.863(3) Ă
, b = 8.036(5)Ă
, c = 18.062(5)Ă
, ÎČ =101.64(1)°, Z = 4 for 7. 197Au Mössbauer data are in good agreement with those for other linear P-Au-Cl containing complexes. The compounds were evaluated for in vitro anti-tumour activity
against two human tumours. Differential cytotoxicity was observed with activity comparable to
cisplatin, with the exception of one compound which was significantly more cytotoxic
Age-related Purkinje cell death is steroid dependent: RORα haplo-insufficiency impairs plasma and cerebellar steroids and Purkinje cell survival
A major problem of ageing is progressive impairment of neuronal function and ultimately cell death. Since sex steroids are neuroprotective, their decrease with age may underlie age-related neuronal degeneration. To test this, we examined Purkinje cell numbers, plasma sex steroids and cerebellar neurosteroid concentrations during normal ageing (wild-type mice, WT), in our model of precocious ageing (Rora+/sg, heterozygous staggerer mice in which expression of the neuroprotective factor RORα is disrupted) and after long-term hormone insufficiency (WT post-gonadectomy). During normal ageing (WT), circulating sex steroids declined prior to or in parallel with Purkinje cell loss, which began at 18 months of age. Although Purkinje cell death was advanced in WT long-term steroid deficiency, this premature neuronal loss did not begin until 9 months, indicating that vulnerability to sex steroid deficiency is a phenomenon of ageing Purkinje neurons. In precocious ageing (Rora+/sg), circulating sex steroids decreased prematurely, in conjunction with marked Purkinje cell death from 9 months. Although Rora+/sg Purkinje cells are vulnerable through their RORα haplo-insufficiency, it is only as they age (after 9 months) that sex steroid failure becomes critical. Finally, cerebellar neurosteroids did not decrease with age in either genotype or gender; but were profoundly reduced by 3 months in male Rora+/sg cerebella, which may contribute to the fragility of their Purkinje neurons. These data suggest that ageing Purkinje cells are maintained by circulating sex steroids, rather than local neurosteroids, and that in Rora+/sg their age-related death is advanced by premature sex steroid loss induced by RORα haplo-insufficiency
Evolution of the central West Greenland margin and the Nuussuaq Basin : Localised basin uplift along a stable continental margin proposed from thermochronological data
ACKNOWLEDGEMENTS Tim Redfield and a second anonymous reviewer are thanked for their constructive comments. The work con-tained in this publication contains work conducted during a PhD study undertaken as part of the Natural Environment Research Council (NERC) Centre for Doctoral Training(CDT) in Oil & Gas [grant number NEM00578X/1] and is sponsored by the University of Aberdeen.Peer reviewedPublisher PD
Whistled Moroccan Tamazight: phonetics and phonology
International audienceThis paper reports the results of a pilot phonetic study of whistled Moroccan Tamazight. Whistled speech is an ancient traditional and natural practice that consists in a phonetic emulation and transformation of the spoken signal into a simple melodic line made up of frequency and amplitude modulations of a whistled signal. It is primarily used for long distance communication. We recorded four Moroccan Tamazight speakers in the High Atlas producing this special speech register. Given its particular characteristics, namely the extensive presence of words and syllables without vowels, the opportunity Tamazight affords for the execution of whistling may be particularly challenging. We show how speakers whistle a selected set of words and sentences and discuss the preliminary results from phonetic and phonological perspectives
Cenozoic (U-Th)/He ages in Lofoten - VesterÄlen islands, Northern Norway
International audienc