Enhanced follicular delivery of finasteride to human scalp skin using heat and chemical penetration enhancers

© The Author(s) 2020. This article is an open access publication. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Purpose The aim of this work was to evaluate whether improved topical delivery of finasteride, focussed to the hair follicles of human scalp skin could be achieved with application of short durations of heat and use of specific chemical penetration enhancers. Methods Franz cell experiments with human scalp skin were performed with a range of chemical penetration enhancers at 32°C and 45°C to simulate normal and heated conditions. Selected chemical penetration enhancers were taken forward for finite dose Franz cell studies which examined the effect of heat produced by a prototype external heating system that supplied either 20 or 30 min of additional heat over both a 24 h and a 1 h time period. Results Short durations of externally applied heat significantly increased finasteride penetration into human scalp skin after 24 h. Analysis of drug distribution in the skin after 1 h and 24 h indicated that both heat and chemical penetration enhancer selection influenced drug delivery to the hair follicles. Conclusion The use of short durations of heat in combination with specific chemical penetration enhancers was able to increase the delivery of finasteride to human scalp skin and provide focussed drug delivery to the hair follicles.Peer reviewe

Hydrokinetic Turbine Effects on Fish Swimming Behaviour

Hydrokinetic turbines, targeting the kinetic energy of fast-flowing currents, are under development with some turbines already deployed at ocean sites around the world. It remains virtually unknown as to how these technologies affect fish, and rotor collisions have been postulated as a major concern. In this study the effects of a vertical axis hydrokinetic rotor with rotational speeds up to 70 rpm were tested on the swimming patterns of naturally occurring fish in a subtropical tidal channel. Fish movements were recorded with and without the rotor in place. Results showed that no fish collided with the rotor and only a few specimens passed through rotor blades. Overall, fish reduced their movements through the area when the rotor was present. This deterrent effect on fish increased with current speed. Fish that passed the rotor avoided the near-field, about 0.3 m from the rotor for benthic reef fish. Large predatory fish were particularly cautious of the rotor and never moved closer than 1.7 m in current speeds above 0.6 ms-1. The effects of the rotor differed among taxa and feeding guilds and it is suggested that fish boldness and body shape influenced responses. In conclusion, the tested hydrokinetic turbine rotor proved non-hazardous to fish during the investigated conditions. However, the results indicate that arrays comprising multiple turbines may restrict fish movements, particularly for large species, with possible effects on habitat connectivity if migration routes are exploited. Arrays of the investigated turbine type and comparable systems should therefore be designed with gaps of several metres width to allow large fish to pass through. In combination with further research the insights from this study can be used for guiding the design of hydrokinetic turbine arrays where needed, so preventing ecological impacts

Ion formation in an argon and argon-oxygen gas mixture of a magnetron sputtering discharge

Formation of singly and doubly charged Arq+ and Tiq+ (q = 1,2) and of molecular Ar 2 +, ArTi+, and Ti 2 + ions in a direct current magnetron sputtering discharge with a Ti cathode and argon as working gas was investigated with the help of energy-resolved mass spectrometry. Measured ion energy distributions consist of low-energy and high-energy components resembling different formation processes. Intensities of Ar 2 + and ArTi+ dimer ions strongly increase with increasing gas pressure. Addition of oxygen gas leads to the formation of positively charged O+, O2 +, and TiO+ and of negatively charged O− and O2 - ions

Growth and properties of Ti-Cu films with respect to plasma parameters in dual-magnetron sputtering discharges

Properties of different methods of magnetron sputtering (dc-MS, dual-MS and dual-HiPIMS) are studied and compared with respect to intermetallic Ti-Cu film formation. The quality and features of thin films are strongly influenced by the energy of incoming particles. The ion velocity distribution functions (IVDFs) were measured by time-resolved retarding field analyzer (RFA) in the substrate position. Thin films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD) and X-ray reflectometry (XR). Properties and crystallography of Ti-Cu films are discussed as a function of ion energy which is affected by the mode of sputtering. It was found that IVDFs measured in pulsed discharges exhibit double-peak distribution. The IVDFs reach the maximum at ion energies about  ~8 eV. The ion saturated current is highest in dual-HiPIMS discharge (~5 μA/cm2) and is mostly represented by Cu+ and Ar+ ions. The mode of sputtering influences chemical composition and film formation. The copper forms polycrystalline fcc-phase while much smaller Ti particles enwraps the copper crystallites or are part of a solid solution

Oral squamous cell carcinoma derived stromal cells influence phenotypic characteristics of keratinocytes

H. Jennings' Whales Scenic - SR38 - photographed 1923. Photograph numbered HB79. See also 178C33.1358 (00240319