Preparation and characterization of microcapsules of Pterodon pubescens Benth. by using natural polymers

An oleaginous fraction obtained from an alcohol extract of the fruit of Pterodon pubescensBenth. (FHPp) was microencapsulated in polymeric systems. These systems were developed using a complex coacervation method and consisted of alginate/medium-molecular-weight chitosan (F1-MC), alginate/chitosan with greater than 75% deacetylation (F2-MC), and alginate/low-molecular-weight chitosan (F3-MC). These developed systems have the potential to both mask the taste of the extract, and to protect its constituents against possible chemical degradation. The influence of the formulation parameters and process were determined by chemical profiling and measurement of the microencapsulation efficiency of the oleaginous fraction, and by assessment of microcapsule morphology. The obtained formulations were slightly yellow, odorless, and had a pleasant taste. The average diameters of the microcapsules were 0.4679 µm (F2-MC), 0.5885 µm (F3-MC), and 0.9033 µm (F1-MC). The best formulation was F3-MC, with FHPp microencapsulation efficiency of 61.01 ± 2.00% and an in vitro release profile of 75.88 ± 0.45%; the content of vouacapans 3-4 was 99.49 ± 2.80%. The best model to describe the release kinetics for F1-MC and F3-MC was that proposed by Higuchi; however, F2-MC release displayed first-order kinetics; the release mechanism was of the supercase II type for all formulations

Optimum high temperature strength of two-dimensional nanocomposites

High-temperature nanoindentation was used to reveal nano-layer size effects on the hardness of two-dimensional metallic nanocomposites. We report the existence of a critical layer thickness at which strength achieves optimal thermal stability. Transmission electron microscopy and theoretical bicrystal calculations show that this optimum arises due to a transition from thermally activated glidewithin the layers to dislocation transmission across the layers.We demonstrate experimentally that the atomic-scale properties of the interfaces profoundly affect this critical transition. The strong implications are that interfaces can be tuned to achieve an optimum in high temperature strength in layered nanocomposite structures

Structure and mechanical properties of swift heavy ion irradiated tungsten-bearing delta-phase oxides Y6W1O12 and Yb6W1O12

We report on the relationship between structure and mechanical properties of complex oxides whose structures are derivatives of fluorite, following irradiation with swift heavy ion (92 MeV Xe) which approximately simulates fission product irradiation, where the electronic energy loss dominates. The two compounds of interest in this paper are Y6W1O12 and Yb6W1O12. These compounds possess an ordered, fluorite derivative crystal structure known as the delta (delta) phase, a rhombohedral structure belonging to space group R (3) over bar

Pharmacokinetics and safety of apremilast (CC-10004) in subjects with hepatic impairment

Apremilast (CC-10004), a PDE4 enzyme inhibitor, is under clinical development for the treatment of inflammatory immune-mediated disorders. Since apremilast is extensively metabolised via multiple routes, impact of hepatic impairment on the pharmacokinetics (PK) of apremilast and M12 metabolite was evaluated. Thirty-two subjects were enrolled in a two-centre, open-label, and single-dose study. Subjects with moderate hepatic impairment and their healthy matches received a single 30-mg dose and subjects with severe hepatic impairment and their healthy matches received a single 20-mg dose of apremilast. Plasma concentrations of apremilast and M12 were measured, PK parameters calculated, and statistically compared. During the study, single doses of apremilast were well tolerated, with no clinically meaningful safety findings observed. PK parameters were comparable between hepatic impaired and healthy subjects, and there was no evidence to suggest that the PK of apremilast is affected by moderate and severe hepatic impairment. Therefore, no dose adjustment is required

The Suppression of Instabilities via Biphase Interfaces During Bulk Fabrication of Nanograined Zr

<div><p>Severe plastic deformation (SPD) is a common method to fabricate nano-grained metals. However for Zr, a structural metal for nuclear applications, obtaining a nanoscale grain structure via SPD has been problematic due to deformation twinning and phase transformations. Here, nanostructured hcp Zr is fabricated through a refinement process via the introduction of a biphase interface. Despite mechanical and thermal conditions known to chemically mix Zr and Nb, no intermixing is observed and the heterophase interfaces appear resistant to phase transformations and twinning. Increasing the density of chemically sharp Zr–Nb interfaces is a very different refinement mechanism than substructure development, stacking fault formation, or alloying.</p></div