Search Results

You are looking at 21 - 30 of 219 items for :

  • Refine by Access: All Content x
Clear All
Journal of Thermal Analysis and Calorimetry
Authors: Berta Holló, Milena Krstić, Sofija P. Sovilj, György Pokol, and Katalin Mészáros Szécsényi

them exhibit even a better cytotoxic effect [ 1 ]. Ruthenium complexes with dimethyl sulfoxide (dmso) showed selective antitumor properties in preclinical testing [ 2 ]. Biological studies in cis - and trans -RuX 2 (dmso) 4 complexes (X = Cl and Br

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Li Bai Xiao, Xiao Ling Xing, Xue Zhong Fan, Feng Qi Zhao, Zhi Ming Zhou, Hai Feng Huang, Ting An, Hai Xia Hao, and Qing Pei

have never been reported so far. Dimethyl sulfoxide (DMSO) and N -methyl pyrrolidone (NMP) as solvents have been used extensively in our production and application, so thermochemical properties of its solution have been studied first by means of a RD

Restricted access

been reported. However, the compounds resulting from the intercalation of small dipolar compounds such as dimethyl sulfoxide (DMSO), N -methylformamide (NMF) or urea can be used as precursors for further intercalations of other organic molecules or

Restricted access

Chapman, J. D., Doren, S. D., Reuvers, A. P., Gillespie, C. J., Chatterjee, A., Blakely, E. A., Smith, K. C., Tobias, C. A. (1979) Radioprotection by DMSO of mammalian cells exposed to X-rays and to heavy charged

Restricted access

Abstract  

To reveal the denaturation mechanism of lysozyme by dimethyl sulfoxide (DMSO), thermal stability of lysozyme and its preferential solvation by DMSO in binary solutions of water and DMSO was studied by differential scanning calorimetry (DSC) and using densities of ternary solutions of water (1), DMSO (2) and lysozyme (3) at 298.15 K. A significant endothermic peak was observed in binary solutions of water and DMSO except for a solution with a mole fraction of DMSO (x 2) of 0.4. As x 2 was increased, the thermal denaturation temperature T m decreased, but significant increases in changes in enthalpy and heat capacity for denaturation, ΔH cal and ΔC p, were observed at low x 2 before decreasing. The obtained amount of preferential solvation of lysozyme by DMSO (∂g 2/∂g 3) was about 0.09 g g−1 at low x 2, indicating that DMSO molecules preferentially solvate lysozyme at low x 2. In solutions with high x 2, the amount of preferential solvation (∂g 2/∂g 3) decreased to negative values when lysozyme was denatured. These results indicated that DMSO molecules do not interact directly with lysozyme as denaturants such as guanidine hydrochloride and urea do. The DMSO molecules interact indirectly with lysozyme leading to denaturation, probably due to a strong interaction between water and DMSO molecules.

Restricted access

sulphoxide (5% v/v DMSO) and groups treated with methanol extracts of DM and MW . The groups treated with DM and MW were given graded dosages of 100, 200 and 400 mg/kg of each methanol extract, respectively. To determine the effects of the vehicle on

Open access

Bruker Auance-II 400 NMR spectrophotometer in DMSO solvent at SAIF Punjab University, Chandigarh while solid reflectance spectra were recorded on a Varian SE UV–NIR spectrophotometer. Magnetic susceptibilities were measured at room temperature by Gouy

Restricted access

Abstract  

Excess enthalpies of sixteen binary mixtures between one each of methyl methylthiomethyl sulfoxide (MMTSO) and dimethyl sulfoxide (DMSO) and one of ketone {CH3CO(CH2)nCH3, n=0 to 6 and CH3COC6H5} have been determined at 298.15 K. All the mixtures showed positive excess enthalpies over the whole range of mole fractions. Excess enthalpies of ketone+MMTSO or DMSO increased with increasing the number of methylene radicals in the methyl alkyl ketone molecules. Excess enthalpies of MMTSO+ketone are smaller than those of DMSO+ketone for the same ketone mixtures. The limiting excess partial molar enthalpies of the ketone, H 1 E,∞, in all the mixtures with MMTSO were smaller than those of DMSO. Linear relationships were obtained between limiting excess partial molar enthalpies and the number of methylene groups except 2-propanone.

Restricted access

Abstract  

A series of new complexes with mixed ligands of the type RuL2(DMSO)mCl3·nH2O ((1) L: norfloxacin (nf), m = 1, n = 1; (2) L: ciprofloxacin (cp), m = 2, n = 2; (3) L: ofloxacin (of), m = 1, n = 1; (4) L: enrofloxacin (enro), m = 0.5, n = 4; DMSO: dimethylsulfoxide) were synthesised and characterised by chemical analysis and IR data. In all complexes both fluoroquinolone derivative and DMSO act as unidentate. The thermal behaviour steps were investigated in synthetic air flow. The thermal transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative and DMSO degradation respectively. The final product of decomposition is ruthenium (IV) oxide.

Restricted access

Abstract  

Dimethylsulfoxide (DMSO) kaolinite complexes of low-and high-defect kaolinites were studied by thermo-IR-spectroscopy analysis. Samples were gradually heated up to 170°C, three hours at each temperature. After cooling to room temperature, they were pressed into KBr disks and their spectra were recorded. From the spectra two types of complexes were identified. In the spectrum of type I complex two bands were attributed to asymmetric and symmetric H-O-H stretching vibrations of intercalated water, bridging between DMSO and the clay-O-planes. As a result of H-bonds between intercalated water molecules and the O-planes, Si-O vibrations of the clay framework were perturbed, in the low-defect kaolinite more than in the high-defect. Type II complex was obtained by the thermal escape of the intercalated water. Consequently, the H-O-H bands were absent from the spectrum of type II complex and the Si-O bands were not perturbed. Type I complex was present up to 120°C whereas type II between 130 and 150°C. The presence of intercalated DMSO was proved from the appearance of methyl bands. These bands decreased with temperature due to the thermal evolution of DMSO but disappeared only in spectra of samples heated at 160°C. Intercalated DMSO was H-bonded to the inner-surface hydroxyls and vibrations associated with this group were perturbed. Due to the thermal evolution of DMSO the intensities of the perturbed bands decreased with the temperature. They disappeared at 160°C together with the methyl bands.

Restricted access