Zinc(II)-methimazole complexes: synthesis and reactivity

The tetrahedral S-coordinated complex [Zn(MeImHS)(4)](ClO4)(2), synthesised from the reaction of [Zn(ClO4)(2)] with methimazole (1-methyl-3H-imidazole-2-thione, MeImHS), reacts with triethylamine to yield the homoleptic complex [Zn(MeImS)(2)] (MeImS = anion methimazole). ESI-MS and MAS C-13-NMR experiments supported MeImS acting as a (N, S)-chelating ligand. The DFT-optimised structure of [Zn(MeImS)(2)] is also reported and the main bond lengths compared to those of related Zn-methimazole complexes. The complex [Zn(MeImS)(2)] reacts under mild conditions with methyl iodide and separates the novel complex [Zn(MeImSMe)(2)I-2] (MeImSMe = S-methylmethimazole). X-ray diffraction analysis of the complex shows a ZnI2N2 core, with the methyl thioethers uncoordinated to zinc. Conversely, the reaction of [Zn( MeImS)(2)] with hydroiodic acid led to the formation of the complex [Zn(MeImHS)(2)I-2] having a ZnI2S2 core with the neutral methimazole units S-coordinating the metal centre. The Zn-coordinated methimazole can markedly modify the coordination environment when changing from its thione to thionate form and vice versa. The study of the interaction of the drug methimazole with the complex [Zn(MeIm)(4)](2+) (MeIm = 1-methylimidazole) - as a model for Zn-enzymes containing a N-4 donor set from histidine residues shows that methimazole displaces only one of the coordinated MeIm molecules; the formation constant of the mixed complex [Zn(MeIm)(3)(MeImHS)](2+) was determined

Gravimetry and petrophysics in the Chad basin area: determination of the basement depth and the implication for defining a scientific drilling site (ICDP-CHADRILL project)

The Chad basin is a huge intracratonic sag-basin (2.5 million km2) in the North Central Africa. In this work, we investigated the basement depth under the Chad Lake using the inversion of gravity residual data obtained by the regression analysis between gravity and topography data. It has been carried on with a collaboration between the University of Trieste and the Institut de Physique du Globe, Strasbourg (IPGS) in order to contribute to the decision of the location of a ICDP drilling site (Bol, SE Chad Lake). This project consists in a compared analysis between gravity data with other geological/geophysical data and their interpretation in terms of tectonic features. The main objectives of this work are: (1) estimation of the basement depth under the Chad basin through a joint analysis and interpretation of satellite and terrestrial gravity data (GOCE, BGI) [1] with borehole data and density values of Cameroon-Chadian rock samples. (2) Estimation and interpretation of the Bouguer and residual gravity anomalies. The results obtained gave us information about the basement depth and the thickness of sediment infill of the basin. Observing the residual values of gravity anomaly field we found a large negative anomaly (-30 mGal) under the Chad basin connected to the presence of low-density sediments. Furthermore, there are several positive anomalies around the edges of the basin [3] and a pattern of linear negative anomalies outside of it. Both types of trends are linked to the presence of rifts and extensional structures. Using the inversion modelling, we could observe a deepening variation of the depth of the basement moving from the southern part (2-3 km) to the northern (4-6 km) one of the Chad Lake. The deepening of the basement is connected to the Termit rift basin and the values are consistent with previous seismic surveys [2]. The depth of the basement under the city of Bol is between 3 and 4 km, but unfortunately, there are no other geological/geophysical constraints to confirm these values. For the drilling purpose, since in the inversion we used a minimum value of the density contrast (200 kg/m3) among the range defined (200-400 kg/m3), it is possible to assume that the maximum expected depth of the basement is about 4 km. We suggest an integrative geophysical survey, such as a seismic reflection campaign to get more detailed information about the structure of the basement (faults, highs and lows) as well as on the variability of its depth and the thickness of the sediment cover

Neurological signs and MRI findings in 12 dogs with multiple myeloma

Vertebral lesions and associated neurological signs occur in dogs with multiple myeloma, however, veterinary literature describing MRI findings is currently lacking. The objective of this multicenter, retrospective, case series study was to describe neurological signs and MRI findings in a group of dogs that presented for spinal pain or other neurological deficits and had multiple myeloma. Electronic records of four veterinary referral hospitals were reviewed. Dogs were included if they had a pathologically confirmed diagnosis of multiple myeloma, had presented for spinal pain or other neurological signs, and had undergone MRI of the vertebral column. The MRI studies were evaluated and the anatomical location of lesion(s), signal intensity, presence of extra‐dural material, degree of spinal cord compression, extent of vertebral lesions, and contrast enhancement were recorded. Twelve dogs met inclusion criteria. Most dogs (n = 8) had a chronic progressive history, with varying degrees of proprioceptive ataxia and paresis (n = 11), and spinal pain was a feature in all dogs. The MRI findings were variable but more consistent features included the presence of multiple expansile vertebral lesions without extension beyond the outer cortical limits of affected vertebrae, and associated extradural material causing spinal cord compression. The majority of lesions were hyper‐ to isointense on T2 (n = 12) and T1‐weighted (n = 8) sequences, with variable but homogeneous contrast‐enhancement (n = 12). These described MRI characteristics of multiple myeloma may be used to aid early identification and guide subsequent confirmatory diagnostic steps, to ultimately improve therapeutic approach and long‐term outcome