Circulation Cooling in Continuous Skin Sonoporation at Constant Coupling Fluid Temperatures.

Exposure of the skin to low-frequency ultrasound in the Franz diffusion cell has been found to increase the permeability of the skin to molecular transport. In many cases, significant heating of the coupling fluid requires the use of duty cycles that extend the total experimental time. This is a methodological study in which the coupling fluid is circulated between a modified Franz diffusion cell and a heat exchanger to allow for the continuous application of low-frequency ultrasound while the coupling fluid temperature is held constant.

A Thermoelectric Device for Coupling Fluid Temperature Regulation During Continuous Skin Sonoporation or Sonophoresis.

During skin sonoporation and sonophoresis, time-consuming duty cycles or fluid replacement is often required to mitigate coupling fluid temperature increases. This study demonstrates an alternative method for temperature regulation: a circulating, thermoelectric system. Porcine skin samples were sonoporated continuously for 10 min at one of three intensities (23.

Photochemical and oxidative cyclisation of tetraphenylpyrroles.

The photochemical and oxidative cyclodehydrogenation reactions of tetraphenylpyrroles act in a complementary fashion for the cyclisation of N-ethyl and N-benzyl derivatives. In the case of the former, a doubly cyclised product was isolated from cyclisation with solid FeCl, while the latter gives a rearranged 3H-pyrrole upon irradiation.

Breath testing and personal exposure--SIFT-MS detection of breath acetonitrile for exposure monitoring.

Breath testing has potential for the rapid assessment of the source and impact of exposure to air pollutants. During the development of a breath test for acetonitrile using selected ion flow tube mass spectrometry (SIFT-MS) raised acetonitrile concentrations in the breath of volunteers were observed that could not be explained by known sources of exposure. Workplace/laboratory exposure to acetonitrile was proposed since this was common to the volunteers with increased breath concentrations.

Variation of guest selectivity within [Fe4L4](8+) tetrahedral cages through subtle modification of the face-capping ligand.

We report here the host-guest behaviour of two isoelectronic [Fe4L4](8+) tetrahedral cages that differ only in the nature of their face-capping ligand and possess either triazine (L1) or benzene (L2) cores. Crystallography reveals these hosts to be flexible and adaptable, while NMR spectroscopy shows them to be selective and discriminating in their host-guest behaviour.

Identification of uric acid as the redox molecule secreted by the yeast Arxula adeninivorans.

The yeast Arxula adeninivorans has been previously shown to secrete a large amount of an electro-active molecule. The molecule was produced by cells that had been cultivated in a rich medium, harvested, washed and then suspended in phosphate-buffered saline (PBS). The molecule was easily detectable after 60 min of incubation in PBS, and the cells continued to produce the molecule in these conditions for up to 3 days.

Endo-β-N-acetylglucosaminidase catalysed glycosylation: tolerance of enzymes to structural variation of the glycosyl amino acid acceptor.

Endo-β-N-Acetylglucosaminidases (ENGases) are highly useful biocatalysts that can be used to synthetically access a wide variety of defined homogenous N-linked glycoconjugates in a convergent manner. The synthetic efficiency of a selection of family GH85 ENGases was investigated as the structure of the acceptor substrate was varied. Several different GlcNAc-asparagine acceptors were synthesised, and used in conjunction with penta- and decasaccharide oxazoline donors.

A face-capped [Fe4L4]8+ spin crossover tetrahedral cage.

Reported here is a face-capped Fe(ii) molecular tetrahedron, [Fe(4)L(4)](BF(4))(8), . Single crystal X-ray diffraction at 153 and 293 K suggest spin crossover (SCO) and variable temperature magnetic susceptibility measurements confirm displays thermally driven SCO behaviour in the solid state and in dilute acetone solution centred around 284-288 K.

Skin peptides of different life stages of Ewing's tree frog.

In frogs, an important mechanism of skin innate immunity against invading microbial pathogens is secretion of antimicrobial peptides from the specialized granular glands. Since these glands develop fully in skin dermis after completion of metamorphosis, they are small and immature in skin of larvae (tadpoles). Skin secretions vary among different life stages.

Large amplitude, proton- and cation-activated latch-type mechanical switches: O-protonated amides stabilized by intramolecular, low-barrier hydrogen bonds within macrocycles.

Large amplitude molecular switches have been developed using oxonium ions as the novel switching mechanism. Macrocycles that contain a polyether ring that are preorganized and of optimum geometry such that strong, linear Low-Barrier Hydrogen Bonds (LBHB, 2.4 to 2.

Using high-performance liquid chromatography to measure the effects of protein-stabilizing cosolvents on a model protein and fluorescent probes.

The effect of cosolvents on the fluorescence of solutes was measured manually and in an automated high-performance liquid chromatography (HPLC) system that eliminates fluorescent contaminants on-line. The HPLC system was used to show that the effect of cosolvents on the fluorescence spectrum of heated chymotrypsin (a measure of unfolding) correlates with the effect of the solutes on the heat stabilization of catalytic activity; r2=0.73 with 12 example cosolvents.