A number of mechanisms have been proposed to explain the phenomenon of frequency aging in the rubidium atomic clock. Helium permeation is one such mechanism. Briefly, the four millitorr of helium in the Earth’s atmosphere can permeate into the resonance cell, changing the clock frequency via the pressure shift of the 0-0 hyperfine transition. On orbit, any He in the resonance cell would permeat...

The available minoxidil formulations for topical application suffer with major drawback having less contact time with the scalp which requires repeated application. Hence, the present study was aimed to investigate the effect of microemulsions and microemulsion based hydrogel systems (MEHs) for increased percutaneous penetration of minoxidil. Minoxidil microemulsions were developed by following...

conclusions according to release exponent n > 1, diffusion mechanism is super case п. the prepared micronized benzoyl peroxide in foamable formulation was stable according to different pharmaceutical evaluation. the emu oil incorporated in this formulation could reduce drawback of bpo (benzoyl peroxide). this formulation could be a good candidate in acne treatment. objectives benzoyl peroxide f...

The enhancing effect of ascorbic acid and triethyl citrate (TEC) on the in vitro skin permeation of rofecoxib across rat epidermis was investigated. Skin pre-treatment with ascorbic acid and TEC at different concentrations, followed by application of rofecoxib gel, showed higher permeation flux than the control condition. The mechanism underlying this permeation enhancement was probed with four...

We describe a novel mechanism for vital fluorescent dye entry into sensory cells and neurons: permeation through ion channels. In addition to the slow conventional uptake of styryl dyes by endocytosis, small styryl dyes such as FM1-43 rapidly and specifically label hair cells in the inner ear by entering through open mechanotransduction channels. This labeling can be blocked by pharmacological ...

We study the permeation dynamics of helium and carbon dioxide through an atomistically detailed model of a polymer of intrinsic microporosity, PIM-1, via non-equilibrium molecular dynamics (NEMD) simulations. This work presents the first explicit molecular modeling of gas permeation through a high free-volume polymer sample, and it demonstrates how permeability and solubility can be obtained co...