This paper reports phase equilibrium measurements and crystal structure analysis on the ionic clathrate hydrate formed from tetra-n-butylphosphonium hydroxide (TBPOH). Phase equilibrium temperatures were measured in the mole fraction range of TBPOH in aqueous solution from 0.0072 to 0.0416. The highest ionic clathrate hydrate−solution equilibrium temperature was determined to be 290.2 K at a TBPOH mole fraction of 0.0340, which corresponds to the congruent composition. Single-crystal X-ray diffraction measurements were performed on the crystal formed at 288.7 K, and the chemical composition of the TBPOH hydrate crystal was determined to be TBPOH·29.6H 2 O, which is consistent with the congruent composition obtained by the phase equilibrium measurement. The crystal structure of the TBPOH hydrate has a superstructure identical with Jeffrey's type I cubic structure, with an I4̅ 3d space group with a lattice constant of 24.5191(13) Å. The TBPOH hydrate structure is compared with the same hydrate structure formed by the tetra-n-butylammonium fluoride. We provide a comprehensive overview of the dissociation temperature, the counteranion, and the hydrate structure regarding TBP and TBA salt hydrates. The dissociation temperatures decrease linearly with the increase in the partial molal volume of anions for TBA and TBP salt hydrates, changing the hydrate structures from the primitive cubic one that has the minimum hydration number.
Gc7 is enriched in striatum and forms a heterotrimeric complex with Ga olf /Gb, which is coupled to D1 receptor (D1R). Here, we attempted to characterize the pathophysiological, neurochemical, and pharmacological features of mice deficient of Gc7 gene. Gc7 knockout mice exhibited age-dependent deficiency in rotarod behavior and increased dystonia-like clasping reflex without loss of striatal neurons. The neurochemical basis for the motor manifestations using immunoblot analysis revealed increased levels of D1R, ChAT and NMDA receptor subunits (NR1 and NR2B) concurrent with decreased levels of D2R and Ga olf , possibly because of the secondary changes of decreased Ga olf /Gc7-mediated D1R transmission. These behavioral and neurochemical changes are closely related to those observed in Huntington's disease (HD) human subjects and HD model mice. Taking advantage of the finding of D2R down-regulation in Gc7 knockout mice and the dopamine-mediated synergistic relationship in the control of locomotion between D2R-striatopallidal and D1R-stritonigral neurons, we hypothesized that D2-agonist pramipexole would reverse behavioral dyskinesia caused by defective D1R/Ga olf signaling. Indeed, the rotarod deficiency and clasping reflex were reversed by pramipexole treatment under chronic administration. These findings suggest that Gc7 knockout mice could be a new type of movement disorders, including HD and useful for the evaluation of therapeutic candidates.
The phase equilibrium temperature and dissociation heat of tetrabutylammonium propionate (TBAPr) hydrate are reported. TBAPr hydrate is a type of ionic semiclathrate hydrates and also could potentially be used as thermal energy storage material. The temperature‐composition phase diagram of the TBAPr hydrate was determined in a defined range of mass fractions. Considering the dissociation heat of differential scanning calorimetry (DSC) measurements, multiple peaks of heat flow were observed in the TBAPr‐water system at the TBAPr mass fraction lower than 0.35, and there was a single peak at the mass fraction higher than 0.37.
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