2,2,2-trifluoroethanol ~TFE! is a commonly used cosolvent in experimental studies of peptides and proteins. Although concentration-dependent TFE effects have been well studied experimentally, the exact mechanism by which TFE affects the solubility and stability of peptides is still unclear. Here we report molecular dynamics simulations of TFE/water mixtures of different composition in an attemp...

Mole fraction solubilities of tadalafil (3) in aqueous mixtures Transcutol® and PEG 400 at temperatures from 298.15 to 333.15 K were analysed following Hildebrand solubility parameters. Cosolvency models for representing various also provided correlation/prediction purposes. Apparent thermodynamic quantities dissolution processes calculated based on van’t Hoff Gibbs equations. Non-linear enthal...

The equilibrium solubility of benzoic acid in water and ethanol, as well nine {ethanol (1) + (2)} mixtures, was determined from T = (293.15 to 323.15) K. Benzoic mole fraction these aqueous-ethanolic mixtures adequately correlated with some well-known correlation/prediction models, obtaining mean percentage deviations 2.2 7.6%. Apparent thermodynamic quantities, namely, Gibbs energy, enthalpy, ...

Spin coherent states play a crucial role in defining QESM (quasi-exactly solvable models) establishing a strict correspondence between energy spectra of spin systems and low-lying quantum states for a particle moving in a potential field of a certain form. Spin coherent states are also used for finding the Wigner-Kirkwood expansion and quantum corrections to energy quantization rules. The close...

The dielectric dispersion ε' and dielectric loss ε" of binary mixture of 1,2-diaminopropane–dimethylaminoethanol were measured by employing the time domain reflectometry technique over a frequency range from 10 MHz to 20 GHz at 288, 298, 308, and 318 K temperatures. The accuracy in the measurement of the ε' and ε" values obtained from this technique is within ±5%. To evaluate various dielectric...

We employ dielectric spectroscopy and molecular dynamic simulations to investigate the dipolar dynamics in the orientationally disordered solid phase of (1,1,2,2)tetrachloroethane. Three distinct orientational dynamics are observed as separate dielectric loss features, all characterized by a simply activated temperature dependence. The slower process, associated to a glassy transition at 156 ± ...

We report experimental studies on the rheology of a few nematic liquid crystals with highly polar molecules (CCH-7, PCH-7, CB-7). The selected molecules have the same alkyl chain (-C(7)H(15)) and cyano (-CN) end group. In the core part of the molecule, CCH-7 has two cyclohexane rings, PCH-7 has one cyclohexane and one aromatic ring, and CB-7 has two aromatic rings. Two viscosities were measured...

A publication by Shanley and Kirkwood (2000) attempts to explain data on caloric restriction (CR) and life extension in the context of the Disposable Soma (DS) theory for the evolution of senescence. As the authors concede, this juxtaposition appears at first to offend intuition: According to the DS theory, senescence is the result of a tight budget for caloric energy, such that repair and main...

The well-known and general ‘‘compressibility theorem’’ for pure substances relates kT 52(] ln V/]p)N,T to a spatial integral involving the pair correlation function g . The isochoric inherent structure formalism for condensed phases separates g (2) into two fundamentally distinct contributions: a generally anharmonic vibrational part, and a structural relaxation part. Only the former determines...

Common input is a widely used concept in motor neurophysiology. It embodies the notion that inputs to individual spinal motor neurons (MNs) are not unique, but partly shared across MNs, and is considered the main explanation for synchronized activity of MNs (Bremner et al. Motor-unit synchronization was first observed in the time domain using cross-correlation histograms from pairs of MNs (Sear...