The medical term onychomycosis should be understood as chronic infection of the nails caused by a fungus. The most common causative agents are the dermatophytes and Candida species. The less common are certain types of moulds (nondermatophyte moulds or NDMs). In approximately 60-80 % of the cases, onychomycosis is due to dermatophytes. Among dermatophytes, the most often isolated causative pathogen is Trichophyton (T.) rubrum. Other common species are T. interdigitale (formerly T. mentagrophytes), Epidermophyton floccosum, and T. tonsurans. The most significant yeasts causing onychomycosis are Candida albicans and Candida parapsilosis. Predisposing factors for onychomycosis include mainly diseases such as diabetes mellitus, peripheral vascular arterial disease, chronic venous insufficiency, polyneuropathies of diverse etiologies, and immunosuppression, e.g., myeloproliferative diseases (such as lymphoma and paraproteinemia), HIV/AIDS, etc. Other factors facilitating the fungal infection are frequent trauma in professional sportsmen, often accompanied by excessive perspiration. The diagnostic methods that are often applied in different dermatologic departments and ambulatory units are also different. This precludes the creation of a unified diagnostic algorithm that could be used everywhere as a possible standard. In most of the cases, the method of choice depends on the specialist's individual experience. The therapeutic approach depends mostly on the fungal organism identified by the dermatologist or mycologist. This review hereby includes the conventional as well as the newest and most reliable and modern methods used for the identification of the pathogens causing onychomycosis. Moreover, detailed information is suggested, about the choice of therapeutic scheme in case whether dermatophytes, moulds, or yeasts have been identified as causative agents. A thorough discussion of the schemes and duration of the antifungal therapy in certain groups of patients have been included.

In order to characterize the complex radiation field produced by heavy-ion beams in water, in particular the lateral dose fall-off and the radiation quality, microdosimetry measurements were performed at GSI Darmstadt using pencil-like beams of 300 MeV/u (12)C and 185 MeV/u (7)Li ions delivered by the heavy-ion synchrotron SIS-18. The ion beams (range in water about 17 cm) were stopped in the center of a 30 x 30 x 30 cm(3) water phantom and their radiation field was investigated by in-phantom measurements using a tissue-equivalent proportional chamber (TEPC). The chamber was placed at 35 different positions in the central plane at various depths along the beam axis and at radial distances of 0, 1, 2, 5 and 10 cm. The off-axis measurements for both (12)C and (7)Li ions show very similar distributions of the lineal energy, all peaking between 1 and 10 keV microm(-1) which is a typical range covered by secondary hydrogen fragments and neutrons. The radiation quality given by the dose-mean lineal energy [Formula in text] was found to be at a constant level of 1-2 keV microm(-1) at radial distances larger than 2 cm. The relative absorbed dose at each position was obtained by integration of the measured spectra normalized to the number of incident primary beam particles. The results confirm that the lateral dose profile of heavy ions shows an extremely steep fall-off, with relative values of about 10(-3), 10(-4) and 10(-5) at the 2, 5 and 10 cm distance from the beam axis, respectively. The depth-dose curves at a fixed distance from the beam axis slowly rise until they reach the depth of the Bragg peak, reflecting the build-up of secondary fragments with increasing penetration depth. The measured (12)C dose profiles were found to be in good agreement with a similar experimental study at HIMAC (Japan).

The reaction of Auoxo6, a dinuclear gold(III) complex, with the model protein bovine pancreatic ribonuclease is explored here by X-ray diffraction and ESI mass spectrometry. Data provide clues on the processes of adduct formation and of enzyme inhibition and, inductively, on the likely mode of action of this metallodrug.

We show that it is possible to transfer the exciton-exciton Coulomb correlation to photons, producing thus pairs of near-gap photons with a high degree of quantum entanglement. The photon pairs emerge from the spontaneous optical decay of biexcitons into two polaritons. The pair intensity-correlations, calculated in the low density limit for a CuCl slab, exhibit quantum features which can be observed by coincidence detection. ᭧ 1999 Published by Elsevier Science Ltd. All rights reserved. Entanglement describes a composite quantum system that cannot be factored into a product of single-particle states and thereby has no classical counterpart. It is manifested by the potential to exhibit correlations that cannot be obtained with classical systems [4]. The theory of quantum information processing lies on entanglement. Teleportation of quantum states [5,6], quantum computation steps [7], quantum cryptography [8] are recent striking applications of entanglement.In this paper, we show that nonlinear correlated excitations in semiconductors can produce entangled near-gap photon pairs. Owing to the possibility of engineering the valence and conduction electronic states of semiconductors opened by modern growth techniques, and owing to the possibility of controlling the exciton-photon interaction in semiconductor microcavities (MCs) [9], the generation of entangled photon pairs in semiconductor systems is expected to be promising towards the realization of integrated quantum-optical devices. In most experiments entanglement has been realized by having the two entangled particles emerging from a common source. In the process here described, the entangled photon pairs emerge from the optical decay of states with two electron-hole (eh) pairs, namely the biexcitons. The quantum process can be schematically described in two steps. First, two incident pump photons, propagating inside the crystal as excitonic polaritons, create a virtual state with two eh pairs. Then the decay of the virtually excited biexcitons can be stimulated by sending an additional light beam (four wave mixing (FWM)) or can be driven by the vacuum fluctuations of the light field (spontaneous hyper Raman scattering (HRS)). The spontaneous optical decay of biexcitons can produce two final polaritons (see Fig. 1) or a longitudinal exciton and a polariton. Energy and

We present a theoretical approach for the simulation of scanning local optical spectroscopy in disordered quantum wells ͑QWs͒. After a single realization of the disorder potential, we calculate spectra on a mesh of points on the QW plane, thus obtaining a three-dimensional matrix of data from which we construct two-dimensional spectroscopic images of excitons laterally localized at interface fluctuations. Our simulations are in close agreement with the experimental findings, and contribute to the interpretation of spatially resolved spectra in QWs. ͓S0003-6951͑00͒04044-4͔Optoelectronics based on very thin active layers of semiconductor, such as quantum wells ͑QWs͒ are now currently used for many commercial applications. The performance of such devices is influenced by interface roughness, impurity concentration, and alloy homogeneity of the QW. Optical spectra of QWs yield valuable information on the quality of the interfaces and the growth process. 1,2 Disorder in a QW results in an effective two dimensional ͑2D͒ potential spatially correlated which tend to localize the center of mass of the exciton. This image was put forth on the basis of detailed theoretical simulations 3-5 and of observed homogeneous and inhomogeneous linewidths. 1 Macroscopic optical probes 1,2 have proven to be powerful techniques for probing localized excitons and hence interface fluctuations of quantum structures, however they perform a spatial averaging of the spectral signal, providing information at best on an inhomogeneous ensemble of quasi-0D ͑zero-dimensional͒ localized exciton states. Recently, techniques of very high spatial resolution optical spectroscopy allowed several groups to study the individual exciton eigenstates laterally localized at interface fluctuations. [6][7][8][9][10][11] Stimulated by the relevance of the experimental results cited above, theoretical approaches modeling the interaction of quantum structures with highly inhomogeneous light fields have been recently presented. 5,[12][13][14][15][16] In this letter, we present theoretical results for scanning local optical spectroscopy in QWs obtained after the simulation of a disorder potential with prescribed statistical properties. We will consider an input light field with a given profile g centered around the beam position R. In experiments done by both illuminating and collecting with the same tip ͑reflec-tion mode͒, the relevant optical signal that can be detected by a general near-field setup is proportional to 17 S ϭ͐dz drP*(r,z)•E(r,z), where P(r,z, ) is the macroscopic polarization of the sample induced by the electromagnetic field E(r,z, ). We have indicated with rϵ(x,y) the projection of the position vector on the plane of the QW and with z the coordinate along the growth direction. Via interferometric techniques it is possible in principle to measure both the phase and the amplitude of S, thus obtaining information on the local complex susceptibility of a sample. 18 Following the general linear response theory, the linear macroscopic polarization P(r...