Hydrated Double Carbonates - A Raman and Infrared Spectroscopic Study

The Raman spectra of selected double carbonates including pirssonite, gaylussite, shortite and quintinite complemented with infrared spectra have been used to characterise the structure of these carbonate minerals. By using a Libowitzky type function hydrogen bond distances for these minerals of 2.669 to 2.766 Å are estimated. The variation in the hydrogen bond distances contributed to the stability of the mineral. The Raman spectrum of pirssonite shows a single band at 1080 cm-1 attributed to the (CO3)2- symmetric stretching mode, in contrast to shortite and quintinite where two bands are observed. Multiple bands are observed for the antisymmetric stretching and bending region for these minerals proving that the carbonate unit is distorted in the structure of pirssonite and gaylussite

Raman spectroscopic study of the uranyl minerals vanmeersscheite U(OH)4[(UO2)3(PO4)2(OH)2] 4H2O and arsenouranylite Ca(UO2)[(UO2)3(AsO4)2(OH)2] (OH)2 6H2O

Raman and infrared spectra of secondary uranyl phosphate vanmeersscheite and Raman spectrum of secondary uranyl arsenate arsenuranylite were recorded and interpreted and the spectra related to the structure of the minerals. Observed bands were attributed to the stretching and bending vibrations of uranyl, phosphate and/or arsenate units and OH (H2O and OH-) units. Phosphuranylite sheet topology is characteristic for both minerals. U-O bond lengths in uranyl were calculated from the spectra and compared with those inferred for vanmeersscheite from the X-ray single crystal structure analysis. O-H...O hydrogen bonds in both minerals were also inferred using the Libowitzky empirical relation

Efficacy of the surgical management of amiodarone-induced thyroiditis.

Aim. Amiodarone, a class III anti-arrhythmic can be a life-saving medication however it can also cause amiodarone-induced thyroiditis (AmIT). Though rare, it is a complex and life-threatening side effect. AmIT can cause significant cardiac dysfunction and lead to cardiac failure. Though generally treated medically, a small sub-group do not respond and their cardiovascular function continues to deteriorate. This select group is referred for a semi-elective total thyroidectomy. Without surgical removal of their thyroid gland these patients will continue to deteriorate, with a 3050% mortality rate for those not operated on. The aim of this study was to assess for any indicators as to when these patients should be referred for total thyroidectomies and the efficacy of this method of treatment. Method. A case series of patients with amiodarone-induced thyroiditis treated with a total thyroidectomy from 19982015 was used to retrospectively assess the efficacy and indicators for surgery. Results. T4 values decreased quickly and significantly after surgery. Patients symptoms mostly resolved after surgery. No clear indicators were found to be common throughout the cohort as to how long medical therapy should be pursued. Conclusion. Clinicians should view surgery as an effective and efficient treatment avenue for amiodarone-induced thyrotoxicosis. However, it is not clear when this treatment should be instigated. A case-by-case approach should be adopted when treating these complicated patients

Characterisation of Ni silicate-bearing minerals by UV-vis-NIR spectrscopy: Effect of Ni substitution in hydrous Ni-Mg silicates

Three Ni silicate-bearing pimelite, nepouite and pecoraite minerals, from Australia have been investigated by UV-Vis-NIR spectroscopy to study the effect of Ni-Mg substitution. The observation of three major absorption bands at 9205-9095 cm-1, 15600-15190 cm-1 and 26550-25660 cm-1 are the characteristic features of Ni2+ in six fold coordination. The effect of cation substitution like Mg2+ for Ni2+ on band shifts in electronic and vibrational spectra enable the distinction between the Ni-bearing silicates

Case-control study of the safety of total thyroidectomy for amiodarone-induced thyroiditis

Aim. Amiodarone, can be a life-saving medication however it can also cause amiodarone-induced thyroiditis (AIT). AIT is a complex and life-threatening side effect which can cause significant cardiac dysfunction and lead to cardiac failure. A small sub-group do not respond to medical therapy and their cardiovascular function continues to deteriorate. This select group is referred for a semi-elective total thyroidectomy. Without surgical removal of their thyroid gland these patients have a 30-50% mortality rate. Though surgery is known to be safer in euthyroid patients, prolongation of medical therapy can lead to worsening of heart function and higher surgical risk. This research aims to evaluate the safety of surgical management of AIT in those who have failed medical treatment. Method. A comparison was made between a group of surgically-treated AIT patients to a group of patients undergoing total thyroidectomies for alternate reasons. The patient demographics, ASA states, weight of the thyroid gland, surgical complications, anaesthetic complications and incidence of thyrotoxic crisis were assessed. Results. This research has shown that a total thyroidectomy is a relatively safe procedure to treat AIT that is not responding to medical therapy. Similar complication rates between the two groups were evident. Coinclusion. Total thyroidectomy is an equivocally safe procedure to perform in patients with AIT. Clinical Significance. Surgeons can consult their patients with realistic risks for their surgery. treating physicians can feel confident that surgery is a safe option for their patients with amiodarone-induced thyroiditis

Raman and infrared spectroscopic study of the anhydrous carbonate minerals shortite and barytocalcite

The Raman spectra of shortite and barytocalcite complimented with infrared spectra have been used to characterise the structure of these carbonate minerals. The Raman spectrum of barytocalcite shows a single band at 1086 cm-1 attributed to the (CO3)2- symmetric stretching mode, in contrast to shortite where two bands are observed. The observation of two bands for shortite confirms the concept of more than one crystallographically distinct carbonate unit in the unit cell. Multiple bands are observed for the antisymmetric stretching and bending region for these minerals proving that the carbonate unit is distorted in the structure of both shortite and barytocalcite