461 research outputs found

    The surgical point of view of the geriatric patient — Urinary incontinence

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    Summary: Background: Urinary incontinence is one of the most frequent diseases in the ageing population. The aim of this manuscript is to present the current knowledge on urinary incontinence regarding (i) prevalence, (ii) pathogenesis, (iii) types, (iv) diagnostic assessment, and (v) treatment options. Methods: The current literature regarding urinary incontinence with special reference to the geriatric patient was reviewed. Results: According to a study performed recently in the Vienna area, 36.0% of women and 11.5% of men aged 70 years or older report urinary incontinence. Several factors, such as urodynamic changes, structural alterations of the lower urinary tract, increased sensory input, and impaired central control of the micturition reflex, contribute to the high prevalence of urinary incontinence with age. The four most common forms of urinary incontinence in the geriatric patient are combined stress/urge incontinence, pure urge incontinence, pure stress incontinence, and overflow incontinence. Diagnostic steps are classified into "mandatory”, "recommended”, and "indicated in selected cases only”. Particularly the "mandatory tests” are simple to perform and need no special equipment. Therapeutic options should be directed to the type of urinary incontinence as well as the physical and mental status of the patient. Conclusions: Urinary incontinence is highly prevalent with age. Conservative treatment is the therapy of choice for urge incontinence and mild to moderate forms of stress and overflow incontinence in the geriatric patien

    Angle‐resolved photoelectron spectroscopy of the core levels of N<sub>2</sub>O

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    We have measured photoionization cross sections and photoelectron asymmetry parameters for each of the core levels of N2O. We have also carried out frozen‐ and relaxed‐core Hartree–Fock studies of these cross sections so as to better understand the underlying shape resonant structure and the role of electronic relaxation in these processes. A broad shape resonance is observed in each of the core‐hole cross sections at 10‐20 eV kinetic energy and there is some evidence of a second shape resonance near the thresholds, an energy region which is not accessible experimentally. The cross sections also exhibit site‐specific behavior with maxima at widely separated photoelectron kinetic energies. These differences probably arise from the fact that photoelectron matrix elements for different core orbitals probe different regions of the shape resonant orbital which extends over the entire molecule. Although the higher energy shape resonances appear quite similar, Hartree–Fock studies show that the central nitrogen resonance is more sensitive to effects of electronic relaxation than the terminal nitrogen or oxygen resonances. Large differences are also seen between the photoelectron asymmetry parameters for the central and terminal atoms

    Angle-resolved photoelectron spectroscopy of the core levels of N_2O

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    We have measured photoionization cross sections and photoelectron asymmetry parameters for each of the core levels of N_2O. We have also carried out frozen‐ and relaxed‐core Hartree–Fock studies of these cross sections so as to better understand the underlying shape resonant structure and the role of electronic relaxation in these processes. A broad shape resonance is observed in each of the core‐hole cross sections at 10‐20 eV kinetic energy and there is some evidence of a second shape resonance near the thresholds, an energy region which is not accessible experimentally. The cross sections also exhibit site‐specific behavior with maxima at widely separated photoelectron kinetic energies. These differences probably arise from the fact that photoelectron matrix elements for different core orbitals probe different regions of the shape resonant orbital which extends over the entire molecule. Although the higher energy shape resonances appear quite similar, Hartree–Fock studies show that the central nitrogen resonance is more sensitive to effects of electronic relaxation than the terminal nitrogen or oxygen resonances. Large differences are also seen between the photoelectron asymmetry parameters for the central and terminal atoms

    Huge impact of compressive strain on phase transition temperatures in epitaxial ferroelectric KxNa1-xNbO3 thin films

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    We present a study in which ferroelectric phase transition temperatures in epitaxial KxNa1-xNbO3 films are altered systematically by choosing different (110)-oriented rare-earth scandate substrates and by variation of the potassium to sodium ratio. Our results prove the capability to continuously shift the ferroelectric-to-ferroelectric transition from the monoclinic MC to orthorhombic c-phase by about 400 °C via the application of anisotropic compressive strain. The phase transition was investigated in detail by monitoring the temperature dependence of ferroelectric domain patterns using piezoresponse force microscopy and upon analyzing structural changes by means of high resolution X-ray diffraction including X-ray reciprocal space mapping. Moreover, the temperature evolution of the effective piezoelectric coefficient d33,f was determined using double beam laser interferometry, which exhibits a significant dependence on the particular ferroelectric phase. © 2019 Author(s)

    A systematic review and meta-analysis of the direct effects of nutrients on corals

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    Chronic exposure of coral reefs to elevated nutrient conditions can modify the performance of the coral holobiont and shift the competitive interactions of reef organisms. Many studies have nowquantified the links between nutrients and coral performance, but fewhave translated these studies to directly address coastal water quality standards. To address this management need, we conducted a systematic review of peer-reviewed studies, public reports, and gray literature that examined the impacts of dissolved inorganic nitrogen (DIN: nitrate, nitrite, and ammonium) and dissolved inorganic phosphorus (DIP: phosphate) on scleractinian corals. The systematic review resulted in 47 studies with comparable data on coral holobiont responses to nutrients: symbiont density, chlorophyll α (chl-α) concentration, photosynthesis, photosynthetic efficiency, growth, calcification, adult survival, juvenile survival, and fertilization. Mixed-effects meta-regression meta-analyses were used to determine the magnitude of the positive or negative effects of DIN and DIP on coral responses. Zooxanthellae density (DIN & DIP), chl-α concentration (DIN), photosynthetic rate (DIN), and growth (DIP) all exhibited positive responses to nutrient addition; maximum quantum yield (DIP), growth (DIN), larval survival (DIN), and fertilization (DIN) exhibited negative responses. In lieu of developing specific thresholds for the management of nutrients as a stressor on coral reefs, we highlight important inflection points in the magnitude and direction of the effects of inorganic nutrients and identify trends among coral responses. The responses of corals to nutrients are complex, warranting conservative guidelines for elevated nutrient concentrations on coral reefs

    Molecular beam epitaxy of GaBiAs on (311) B GaAs substrates

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    We report the growth by molecular beam epitaxy of Ga Bix As1-x epilayers on (311) B GaAs substrates. We use high-resolution x-ray diffraction (HRXRD), transmission electron microscopy, and Z -contrast imaging to characterize the structural properties of the as-grown material. We find that the incorporation of Bi into the GaBiAs alloy, as determined by HRXRD, is sizably larger in the (311) B epilayers than in (001) epilayers, giving rise to reduced band-gap energies as obtained by optical transmission spectroscopy. © 2007 American Institute of Physics

    Surface effects of vapour-liquid-solid driven Bi surface droplets formed during molecular-beam-epitaxy of GaAsBi

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    Herein we investigate a (001)-oriented GaAs1−xBix/GaAs structure possessing Bi surface droplets capable of catalysing the formation of nanostructures during Bi-rich growth, through the vapourliquid-solid mechanism. Specifically, self-aligned “nanotracks” are found to exist trailing the Bi droplets on the sample surface. Through cross-sectional high-resolution transmission electron microscopy the nanotracks are revealed to in fact be elevated above surface by the formation of a subsurface planar nanowire, a structure initiated mid-way through the molecular-beam-epitaxy growth and embedded into the epilayer, via epitaxial overgrowth. Electron microscopy studies also yield the morphological, structural, and chemical properties of the nanostructures. Through a combination of Bi determination methods the compositional profile of the film is shown to be graded and inhomogeneous. Furthermore, the coherent and pure zincblende phase property of the film is detailed. Optical characterisation of features on the sample surface is carried out using polarised micro-Raman and micro-photoluminescence spectroscopies. The important light producing properties of the surface nanostructures are investigated through pump intensity-dependent micro PL measurements, whereby relatively large local inhomogeneities are revealed to exist on the epitaxial surface for important optical parameters. We conclude that such surface effects must be considered when designing and fabricating optical devices based on GaAsBi alloys

    Diagnostik und Therapie von Pseudotumoren der Orbita

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