Magnetic properties of GaMnAs single layers and GaInMnAs superlattices investigated at low temperature and high magnetic field

Magnetotransport properties of GaMnAs single layers and InGaMnAs/InGaAs superlattice structures were investigated at temperatures from 4 K to 300 K and magnetic fields up to 23 T to study the influence of carriers confinement through different structures. Both single layers and superlattice structures show paramagnetic-to-ferromagnetic phase transition. In GaMnAs/InGaAs superlattice beside the Curie temperature (Tc ~ 40 K), a new phase transition is observed close to 13 K.Comment: 8 pages, 5 figures, Proceedings of the XXXII International School on the Physics of Semiconducting Compounds, Jaszowiec 2003, Polan

Post-growth annealing of GaMnAs under As capping - an alternative way to increase Tc

We demonstrate that in situ post-growth annealing of GaMnAs layers under As capping is adequate for achieving high Curie temperatures (Tc) in a similar way as ex situ annealing in air or in N2 atmosphere practiced earlier.Comment: 13 pages, 4 figure

Neuromodulation in Urology: Current Trends and Future Applications

Urological applications of neuromodulation and neurostimulation are among the most evolving fields for these technologies. First approved for management of refractory urge incontinence, different modalities of neuromodulation and stimulation have been tested, applied and verified for a vast spectrum of voiding and pelvic floor dysfunction disorders. The modalities of delivering this treatment have also evolved in the last three decades, with a focus on sacral neuromodulation. The experimental and established “off-label” applications of neuromodulation have also encompassed chronic pelvic pain disorders, including chronic prostatitis and bladder pain syndrome, among others. In this chapter, we discuss all the hypothesized theories suggested on how this technology provides therapeutic potential for a number of chronic and debilitating urological conditions, the modes of delivery be it anterior, sacral, and posterior tibial to name a few, and the evolving and future applications

Urological Applications of Botulinum Toxin A

Botulinum toxin A (BoNT-A) has seen in the last two decades an increased level of application in urological practice, first FDA approved in 2011 for neurogenic detrusor overactivity and then later in 2013 for refractory overactive bladder. Hundreds of studies have been published in literature assessing the chemical structure of botulinum toxins and how urothelial injections in the lower urinary tract and vesical instillations can be employed in the management of a spectrum of urological conditions particularly voiding dysfunction. The consensus is still out on toxin A preparations, mode and pattern of application whether instilled or injected intradetrusally, units used, as well as time to onset and duration of effect of injections and is still a dense research topic. This is reflected in the continuously changing and differing grades of recommendations between societies of urological practitioners such as the EAU and AUA, among others. This chapter discusses both the FDA-approved and experimental applications of botulinum toxin A in urology, indications, techniques, and points of debate

Structure and dynamics of a model glass: influence of long-range forces

We vary the amplitude of the long-range Coulomb forces within a classical potential describing a model silica glass and study the consequences on the structure and dynamics of the glass, via molecular dynamics simulations. This model allows us to follow the variation of specific features such as the First Sharp Diffraction Peak and the Boson Peak in a system going continuously from a fragile (no Coulomb forces) to a strong (with Coulomb forces) glass. In particular we show that the characteristic features of a strong glass (existence of medium range order, bell-shaped ring size distribution, sharp Boson peak) appear as soon as tetrahedral units are formed.Comment: 5 pages, 4 figures. To be published in J.Phys.: C

Harmonic Vibrational Excitations in Disordered Solids and the "Boson Peak"

We consider a system of coupled classical harmonic oscillators with spatially fluctuating nearest-neighbor force constants on a simple cubic lattice. The model is solved both by numerically diagonalizing the Hamiltonian and by applying the single-bond coherent potential approximation. The results for the density of states $g(\omega)$ are in excellent agreement with each other. As the degree of disorder is increased the system becomes unstable due to the presence of negative force constants. If the system is near the borderline of stability a low-frequency peak appears in the reduced density of states $g(\omega)/\omega^2$ as a precursor of the instability. We argue that this peak is the analogon of the "boson peak", observed in structural glasses. By means of the level distance statistics we show that the peak is not associated with localized states