Geomagnetic disturbances on ground associated with particle precipitation during SC

We have examined several cases of magnetosphere compression by solar wind pressure pulses using a set of instruments located in the noon sector of auroral zone. We have found that the increase in riometric absorption (sudden commencement absorption, SCA) occurred simultaneously with the beginning of negative or positive magnetic variations and broadband enhancement of magnetic activity in the frequency range above 0.1 Hz. Since magnetic variations were observed before the step-like increase of magnetic field at equatorial station (main impulse, MI), the negative declinations resembled the so-called preliminary impulse, PI. In this paper a mechanism for the generation of PI is introduced whereby PI's generation is linked to SCA – associated precipitation and the local enhancement of ionospheric conductivity leading to the reconstruction of the ionospheric current system prior to MI. Calculation showed that PI polarity depends on orientation of the background electric field and location of the observation point relative to ionospheric irregularity. For one case of direct measurements of electric field in the place where the ionospheric irregularity was present, the sign of calculated disturbance corresponded to the observed one. High-resolution measurements on IRIS facility and meridional chain of the induction magnetometers are utilized for the accurate timing of the impact of solar wind irregularity on the magnetopause

Effect of Zeta Potential on the Properties of Nano-Drug Delivery Systems - A Review (Part 1)

Zeta potential is a scientific term for electrokinetic potential in colloidal systems which has a major effect on the various properties of nano-drug delivery systems. Presently, colloidal nano-carriers are growing at a remarkable rate owing to their strong potential for overcoming old challenges such as poor drug solubility and bioavailability. Furthermore, they show an unlimited capacity in the field of drug targeting. The properties of nano-medicines such as release from dosage forms at specific sites as well as drug circulation and absorption into body membranes are dramatically affected by some physical and chemical characteristics of nano-drugs. Particle size and charge are two major factors which could play key roles in this regard. In this paper, the effect of zeta potential on different properties of nano-drug delivery systems is reviewed.Keywords: Nano-drug delivery, Zeta potential, Drug targeting, Particle size, Particle charg

Effect of Zeta Potential on the Properties of Nano-Drug Delivery Systems - A Review (Part 2)

The zeta potential (ZP) of colloidal systems and nano-medicines, as well as their particle size exert a major effect on the various properties of nano-drug delivery systems. Not only the stability of dosage forms and their release rate are affected but also their circulation in the blood stream and absorptioninto body membranes are dramatically altered by ZP. In this paper the effect of ZP on the various properties of nano-medicines are reviewed. Furthermore, the ability of employing zeta potential to target drug delivery systems to, and drug release at specific sites of the body are discussed.Keywords: Nano-medicines, Zeta potential, Drug targeting, Site-specific release, Dosage form stabilit