[Chronic posttraumatic shoulder instability]. / Chronische posttraumatische Schulterinstabilität.

Chronic posttraumatic shoulder instability is characterized by trauma-associated, recurrent dislocations. Surgical treatment is indicated in most cases but it remains controversial how risk factors should be weighted to decide between arthroscopic Bankart repair (ABR), Latarjet or alternative procedures. Known risk factors for recurrence are patient age, hyperlaxity, sports profile and bone loss. Surgical techniques are discussed in detail. The ABR leads to high patient satisfaction and return to sports; however, in association with risk factors, recurrent dislocations are seen even several years later. Latarjet or bone block procedures lead to high patient satisfaction, sustainable stability as a revision procedure, but can also be primarily indicated for chronic instability depending on risk factors. Early complications are more frequent but of a minor nature in most cases. All techniques are known for a serious learning curve. If performed well, they do not seem to increase the risk of arthritis, which is most affected by the number of lifetime dislocations and higher energy trauma.

Partial Time-Reversal Invariance Violation in a Flat, Superconducting Microwave Cavity with the Shape of a Chaotic Africa Billiard.

We report on the experimental realization of a flat, superconducting microwave resonator, a microwave billiard, with partially violated time-reversal (T) invariance, induced by inserting a ferrite into the cavity and magnetizing it with an external magnetic field perpendicular to the resonator plane. In order to prevent its expulsion caused by the Meissner-Ochsenfeld effect, we used a cavity of which the top and bottom plate were made from niobium, a superconductor of type II, and cooled it down to liquid-helium temperature T_{LHe}≃4 K. The cavity had the shape of a chaotic Africa billiard. Superconductivity rendered possible the accurate determination of complete sequences of the resonance frequencies and of the widths and strengths of the resonances, an indispensable prerequisite for the unambiguous detection of T invariance violation, especially when it is only partially violated. This allows for the first time the precise specification of the size of T invariance violation from the fluctuation properties of the resonance frequencies and from the strength distribution, which actually depends sensitively on it and thus provides a most suitable measure. For this purpose we derived an analytical expression for the latter which is valid for isolated resonances in the range from no T invariance violation to complete violation.

Chaos and Regularity in the Doubly Magic Nucleus

High-resolution experiments have recently lead to a complete identification (energy, spin, and parity) of 151 nuclear levels up to an excitation energy of E_{x}=6.20 MeV in ^{208}Pb [Heusler et al., Phys. Rev. C 93, 054321 (2016)PRVCAN2469-998510.1103/PhysRevC.93.054321]. We present a thorough study of the fluctuation properties in the energy spectra of the unprecedented set of nuclear bound states. In a first approach, we group states with the same spin and parity into 14 subspectra, analyze standard statistical measures for short- and long-range correlations, i.e., the nearest-neighbor spacing distribution, the number variance Σ^{2}, the Dyson-Mehta Δ_{3} statistics, and the novel distribution of the ratios of consecutive spacings of adjacent energy levels in each energy sequence, and then compute their ensemble average. Their comparison with a random matrix ensemble which interpolates between Poisson statistics expected for regular systems and the Gaussian orthogonal ensemble (GOE) predicted for chaotic systems shows that the data are well described by the GOE. In a second approach, following an idea of Rosenzweig and Porter [Phys. Rev. 120, 1698 (1960)PHRVAO0031-899X10.1103/PhysRev.120.1698], we consider the complete spectrum composed of the independent subspectra. We analyze their fluctuation properties using the method of Bayesian inference involving a quantitative measure, called the chaoticity parameter f, which also interpolates between Poisson (f=0) and GOE statistics (f=1). It turns out to be f≈0.9. This is so far the closest agreement with a GOE observed in the spectra of bound states in a nucleus. The same analysis is also performed with spectra computed on the basis of shell model calculations with different interactions (surface-delta interaction, Kuo-Brown, Michigan-three-Yukawa). While the simple surface-delta interaction exhibits features typical for nuclear many-body systems with regular dynamics, the other, more realistic interactions yield chaoticity parameters f close to the experimental values.

[Dementia-friendly hospital wards : Expert recommendations for planning and design]. / Demenzsensible Krankenhausstationen : Expertenempfehlungen zu Planung und Gestaltung.

BACKGROUND: Hospitals face great challenges in the necessity of providing care for the rising number of elderly patients with dementia. The adaptation of the spatial environment represents an important component to improve the care situation of patients with dementia. For more than 30 years research results from long-term care have provided evidence on the therapeutic effect of numerous architectural features on people with dementia. Due to specific medical and organizational requirements in hospitals, the transferability of these findings is, however, limited. MATERIAL AND METHODS: An interdisciplinary workshop with experts from the fields of medicine, nursing, gerontology, self-help and architecture was conducted in July 2015. Based on existing research findings and experiences from pilot projects, the spatial requirements for dementia-friendly hospital wards were collated, suggested solutions were discussed from different perspectives and finally design recommendations were derived. RESULTS: The article gives a first comprehensive overview of architectural measures that are required for the design of dementia-friendly hospital wards. The recommendations provided range from architectural criteria, such as the size and spatial structure of hospital wards, to interior design elements, including orientation and navigation aids and the use of light and colors. Furthermore, information about the planning process are given.

Spectral Properties of Dirac Billiards at the van Hove Singularities.

We study distributions of the ratios of level spacings of rectangular and Africa-shaped superconducting microwave resonators containing circular scatterers on a triangular grid, so-called Dirac billiards (DBs). The high-precision measurements allowed the determination of, respectively, all 1651 and 1823 eigenfrequencies in the first two bands. The resonance densities are similar to that of graphene. They exhibit two sharp peaks at the van Hove singularities which separate the band structure into regions with a linear and a quadratic dispersion relation, respectively. In the vicinity of the van Hove singularities we observe rapid changes in, e.g., the wave function structure. Accordingly, we question whether the spectral properties are there still determined by the shapes of the DBs. The commonly used statistical measures are no longer applicable; however, we demonstrate in this Letter that the ratio distributions provide suitable measures.

Quantum and wave dynamical chaos in superconducting microwave billiards.

Experiments with superconducting microwave cavities have been performed in our laboratory for more than two decades. The purpose of the present article is to recapitulate some of the highlights achieved. We briefly review (i) results obtained with flat, cylindrical microwave resonators, so-called microwave billiards, concerning the universal fluctuation properties of the eigenvalues of classically chaotic systems with no, a threefold and a broken symmetry; (ii) summarize our findings concerning the wave-dynamical chaos in three-dimensional microwave cavities; (iii) present a new approach for the understanding of the phenomenon of dynamical tunneling which was developed on the basis of experiments that were performed recently with unprecedented precision, and finally, (iv) give an insight into an ongoing project, where we investigate universal properties of (artificial) graphene with superconducting microwave photonic crystals that are enclosed in a microwave resonator, i.e., so-called Dirac billiards.

Cross-section fluctuations in open microwave billiards and quantum graphs: The counting-of-maxima method revisited.

The fluctuations exhibited by the cross sections generated in a compound-nucleus reaction or, more generally, in a quantum-chaotic scattering process, when varying the excitation energy or another external parameter, are characterized by the width Γcorr of the cross-section correlation function. Brink and Stephen [Phys. Lett. 5, 77 (1963)] proposed a method for its determination by simply counting the number of maxima featured by the cross sections as a function of the parameter under consideration. They stated that the product of the average number of maxima per unit energy range and Γcorr is constant in the Ercison region of strongly overlapping resonances. We use the analogy between the scattering formalism for compound-nucleus reactions and for microwave resonators to test this method experimentally with unprecedented accuracy using large data sets and propose an analytical description for the regions of isolated and overlapping resonances.

Fullerene C(60) Simulated with a Superconducting Microwave Resonator and Test of the Atiyah-Singer Index Theorem.

We report first experiments with a macroscopic-size superconducting microwave resonator that has the geometric structure of the C(60) fullerene molecule. Our high-resolution measurements reveal the exceptional spectral properties that stem from the icosahedral symmetry of its carbon lattice. In particular, they allow us to determine the number of zero-energy modes, i.e., of modes with energy values at the Dirac point existent in the band structure due to the hexagonal arrangements of the carbon atoms, and to test the Atiyah-Singer index theorem which relates this number to the topology of the curved carbon lattice.

Dielectric square resonator investigated with microwave experiments.

We present a detailed experimental study of the symmetry properties and the momentum space representation of the field distributions of a dielectric square resonator as well as the comparison with a semiclassical model. The experiments have been performed with a flat ceramic microwave resonator. Both the resonance spectra and the field distributions were measured. The momentum space representations of the latter evidenced that the resonant states are each related to a specific classical torus, leading to the regular structure of the spectrum. Furthermore, they allow for a precise determination of the refractive index. Measurements with different arrangements of the emitting and the receiving antennas were performed and their influence on the symmetry properties of the field distributions was investigated in detail, showing that resonances with specific symmetries can be selected purposefully. In addition, the length spectrum deduced from the measured resonance spectra and the trace formula for the dielectric square resonator are discussed in the framework of the semiclassical model.

Spectral properties and dynamical tunneling in constant-width billiards.

We determine with unprecedented accuracy the lowest 900 eigenvalues of two quantum constant-width billiards from resonance spectra measured with flat, superconducting microwave resonators. While the classical dynamics of the constant-width billiards is unidirectional, a change of the direction of motion is possible in the corresponding quantum system via dynamical tunneling. This becomes manifest in a splitting of the vast majority of resonances into doublets of nearly degenerate ones. The fluctuation properties of the two respective spectra are demonstrated to coincide with those of a random-matrix model for systems with violated time-reversal invariance and a mixed dynamics. Furthermore, we investigate tunneling in terms of the splittings of the doublet partners. On the basis of the random-matrix model we derive an analytical expression for the splitting distribution which is generally applicable to systems exhibiting dynamical tunneling between two regions with (predominantly) chaotic dynamics.

Scattering experiments with microwave billiards at an exceptional point under broken time-reversal invariance.

Scattering experiments with microwave cavities were performed and the effects of broken time-reversal invariance (TRI), induced by means of a magnetized ferrite placed inside the cavity, on an isolated doublet of nearly degenerate resonances were investigated. All elements of the effective Hamiltonian of this two-level system were extracted. As a function of two experimental parameters, the doublet and the associated eigenvectors could be tuned to coalesce at a so-called exceptional point (EP). The behavior of the eigenvalues and eigenvectors when encircling the EP in parameter space was studied, including the geometric amplitude that builds up in the case of broken TRI. A one-dimensional subspace of parameters was found where the differences of the eigenvalues are either real or purely imaginary. There, the Hamiltonians were found to be PT invariant under the combined operation of parity (P) and time reversal (T) in a generalized sense. The EP is the point of transition between both regions. There a spontaneous breaking of PT occurs.

Depolarizing chloride gradient in developing cochlear nucleus neurons: underlying mechanism and implication for calcium signaling.

Precise regulation of the chloride homeostasis crucially determines the action of inhibitory transmitters GABA and glycine and thereby endows neurons or even discrete neuronal compartments with distinct physiological responses to the same transmitters. In mammals, the signaling mediated by GABAA/glycine receptors shifts during early postnatal life from depolarization to hyperpolarization, due to delayed maturation of the chloride homeostasis system. While the activity of the secondary active, K(+)-Cl(-)-extruding cotransporter KCC2, renders GABA/glycine hyperpolarizing in auditory brainstem nuclei of altricial rodents, the mechanisms contributing to the initially depolarizing transmembrane gradient for Cl(-) in respective neurons remained unknown. Here we used gramicidin-perforated patch recordings, non-invasive Cl(-) and Ca(2+) imaging, and immunohistochemistry to identify the Cl(-)-loading transporter that renders depolarizing effects of GABA/glycine in early postnatal life of spherical bushy cells in the cochlear nucleus of gerbil. Our data identify the 1Na(+):1K(+):2Cl(-) cotransporter 1 (NKCC1) as the major Cl(-)-loader responsible for depolarizing action of GABA/glycine at postnatal days 3-5 (P3-5). Extracellular GABA/muscimol elicited calcium signaling through R-, L-, and T-type channels, which was dependent on bumetanide- and [Na(+)]e-sensitive Cl(-) accumulation. The "adult like", low intracellular Cl(-) concentration is established during the second postnatal week, through a mechanism engaging the NKCC1-down regulation between P5 and P15 and ongoing KCC2-mediated Cl(-)-extrusion.

Distribution of scattering matrix elements in quantum chaotic scattering.

Scattering is an important phenomenon which is observed in systems ranging from the micro- to macroscale. In the context of nuclear reaction theory, the Heidelberg approach was proposed and later demonstrated to be applicable to many chaotic scattering systems. To model the universal properties, stochasticity is introduced to the scattering matrix on the level of the Hamiltonian by using random matrices. A long-standing problem was the computation of the distribution of the off-diagonal scattering-matrix elements. We report here an exact solution to this problem and present analytical results for systems with preserved and with violated time-reversal invariance. Our derivation is based on a new variant of the supersymmetry method. We also validate our results with scattering data obtained from experiments with microwave billiards.

Bound states in sharply bent waveguides: analytical and experimental approach.

Quantum wires and electromagnetic waveguides possess common features since their physics is described by the same wave equation. We exploit this analogy to investigate experimentally with microwave waveguides and theoretically with the help of an effective potential approach the occurrence of bound states in sharply bent quantum wires. In particular, we compute the bound states, study the features of the transition from a bound to an unbound state caused by the variation of the bending angle, and determine the critical bending angles at which such a transition takes place. The predictions are confirmed by calculations based on a conventional numerical method as well as experimental measurements of the spectra and electric field intensity distributions of electromagnetic waveguides.

Development and validation of the chronic hepatitis C virus treatment satisfaction (HCVTSat) instrument.

BACKGROUND: While current medications used to treat patients with chronic hepatitis C virus (HCV) effectively produce sustained viral response (SVR), postponement of therapy is often times attributed to patient perceptions of unfavourable outcomes. However, an instrument to assess patient perceptions of therapy (i.e. treatment satisfaction) has not been developed. AIM: To describe the development and validation the chronic Hepatitis C Virus Treatment Satisfaction (HCVTSat) instrument. METHODS: Focus groups, expert review and cognitive debriefing were used to develop a draft 37-item instrument (scale: 1 = not important at all; 5 = extremely important). The preliminary instrument was administered to a pre-test sample of 145 patients through Mayo Clinic, Rochester, MN. A refined HCVTSat was administered to a main sample of 333 participants with a chronic HCV diagnosis through Harris Interactive. RESULTS: The HCVTSat was completed by 333 participants with an average age of 51 (s.d. = 12.1) years, 55% male, current or previous HCV treatment experience, and a diagnosis of HCV for approximately 12 (s.d. = 8.9) years. Twelve items for the 3 dimensions, Treatment Experience (TE), Side Effects (SE) and Social Aspects (SA), were internally consistent (Cronbach's α range: 0.70-0.90), responsive and valid. Confirmatory factor analysis (goodness-of-fit indexes: χ(2) = 20.9, df = 23, P = 0.59; CFI = 1.00, GFI = 0.99, TFI = 1.00, RMSEA = 0.001) revealed a better fit with 9 items. All path coefficients were significant (P < 0.05). SE and SA were strong predictors of TE, while TE was positively associated with the 1-item global measure of TS (path coefficient = 0.12). CONCLUSIONS: The 10-item HCVTSat demonstrated valid psychometric properties and assessed patient satisfaction with HCV therapies. However, additional studies are needed to validate the HCVTSat in conjunction with SVR and in patients in underrepresented populations.

Experimental observation of localized modes in a dielectric square resonator.

We investigated the frequency spectra and field distributions of a dielectric square resonator in a microwave experiment. Since such systems cannot be treated analytically, the experimental studies of their properties are indispensable. The momentum representation of the measured field distributions shows that all resonant modes are localized on specific classical tori of the square billiard. Based on these observations a semiclassical model was developed. It shows excellent agreement with all but a single class of measured field distributions that will be treated separately.

Trace formula for chaotic dielectric resonators tested with microwave experiments.

We measured the resonance spectra of two stadium-shaped dielectric microwave resonators and tested a semiclassical trace formula for chaotic dielectric resonators proposed by Bogomolny et al. [Phys. Rev. E 78, 056202 (2008)]. We found good qualitative agreement between the experimental data and the predictions of the trace formula. Deviations could be attributed to missing resonances in the measured spectra in accordance with previous experiments [Phys. Rev. E 81, 066215 (2010)]. The investigation of the numerical length spectrum showed good qualitative and reasonable quantitative agreement with the trace formula. It demonstrated, however, the need for higher-order corrections of the trace formula. The application of a curvature correction to the Fresnel reflection coefficients entering the trace formula yielded better agreement, but deviations remained, indicating the necessity of further investigations.

Economic and health-related quality-of-life (HRQoL) comparison of lopinavir/ritonavir (LPV/r) and atazanavir plus ritonavir (ATV+RTV) based regimens for antiretroviral therapy (ART)-naïve and -experienced United Kingdom patients in 2011.

BACKGROUND: Using a United Kingdom (UK)-based National Health Services perspective for 2011 this study first estimated the cost-effectiveness and budget impact implications for lopinavir/ritonavir (LPV/r) vs atazanavir plus ritonavir (ATV+RTV) treatment of antiretroviral therapy (ART)-naïve patients and secondly examined the long-term health-related quality-of-life (HRQoL) and economic implications for LPV/r vs ATV+RTV treatment of ART-experienced patients. METHODS: A previously published Markov model that integrates epidemiological data of human immunodeficiency virus (HIV) with predictors of coronary heart disease (CHD) was modified under a clearly specified set of assumptions to reflect viral load (VL) suppression profiles and other differences for these two regimens, applying results from the CASTLE study in ART-naïve patients and using data from BMS-045 in ART-experienced patients. ART costs were referenced to current (2011) pricing guidelines in the UK. Medical care costs reflected UK treatment patterns and relevant drug pricing. Costs and outcomes were discounted at 3.5% per year. Costs are expressed in British pounds (£) and life expectancy in quality-adjusted life years (QALYs). RESULTS: In the ART-naïve subjects, the model predicted a marginal improved life expectancy of 0.031 QALYs (11 days) for the ATV+RTV regimen as a result of predicted CHD outcomes based on lower increases in cholesterol levels compared with the LPV/r regimen. The model demonstrated cost savings with the LPV/r regimen. The total lifetime cost savings was £4070 per patient for the LPV/r regimen. LPV/r saved £2133 and £3409 per patient at 5 and 10 years, respectively. Referenced to LPV/r, the incremental cost-effectiveness ratio (ICER) for ATV+RTV was £149,270/QALY. For ART-experienced patients VL suppression differences favored LPV/r, while CHD risk associated with elevated total cholesterol marginally favored ATV+RTV, resulting in a net improvement in life expectancy of 0.31 QALYs (106 days) for LPV/r. Five-year costs were £5538 per patient greater for ATV+RTV, with a discounted lifetime saving of £1445 per LPV/r patient. LPV/r was modestly dominant economically, producing better outcomes and cost savings. LIMITATIONS: The limitations of this study include uncertainty related to how well the model's assumptions capture current practice, as well as the validity of the model parameters used. This study was limited to using aggregated data in the public domain from the two clinical trials. Thus, some of the model parameters may reflect limitations due to trial design and data aggregation bias. This study has attempted to illuminate the effect of these limitations by presenting the results of the comprehensive sensitivity analysis. CONCLUSIONS: Based on 2011 costs of HIV in the UK and the published efficacy data from the CASTLE and BMS-045 studies, ATV+RTV-based regimens are not expected to be a cost-effective use of resources for ART-naïve patients similar to patients in the CASTLE study, nor for ART-experienced patients based on the only published comparison of ATV+RTV and LPV/r.

Application of a trace formula to the spectra of flat three-dimensional dielectric resonators.

The length spectra of flat three-dimensional dielectric resonators of circular shape were determined from a microwave experiment. They were compared to a semiclassical trace formula obtained within a two-dimensional model based on the effective index of refraction approximation and a good agreement was found. It was necessary to take into account the dispersion of the effective index of refraction for the two-dimensional approximation. Furthermore, small deviations between the experimental length spectrum and the trace formula prediction were attributed to the systematic error of the effective index of refraction approximation. In summary, the methods developed in this article enable the application of the trace formula for two-dimensional dielectric resonators also to realistic, flat three-dimensional dielectric microcavities and -lasers, allowing for the interpretation of their spectra in terms of classical periodic orbits.