[Ultrasound diagnostics for myotendinous injuries and insertion tendinopathies of the elbow joint]. / Ultraschalldiagnostik bei muskuloligamentären Verletzungen sowie Insertionstendinopathien am Ellenbogengelenk.

INTRODUCTION: Acute capsular injuries of the elbow joint and its ligaments predominantly occur after joint dislocation or subluxation. Together with lateral and medial epicondylitis they represent a common injury pattern in radiology, orthopedic and trauma surgery. CLINICAL ISSUE: Because of the complexity of the elbow joint, knowledge of the elbow dislocation and injury pattern as well as the anatomy is essential in order to adequately estimate the injury severity and joint stability. This is crucial for the correct diagnosis and choice of treatment. Systematic physical examination and careful radiographic evaluation are components of an adequate management of acute soft tissue elbow injuries. DIAGNOSTIC WORK-UP: The cost-effective ultrasound has emerged as a useful imaging modality for the diagnosis of acute joint and soft tissue pathologies especially in the acute phase after injury. Ultrasound as a diagnostic tool enables visualization of motion sequences during dynamic examination and therefore a better understanding of pathologies. Ultrasound examinations of the most common injuries of the elbow joint are presented in this overview.

Rise Time Reduction of Thermal Actuators Operated in Air and Water through Optimized Pre-Shaped Open-Loop Driving.

Electrothermal actuators have many advantages compared to other actuators used in Micro-Electro-Mechanical Systems (MEMS). They are simple to design, easy to fabricate and provide large displacements at low voltages. Low voltages enable less stringent passivation requirements for operation in liquid. Despite these advantages, thermal actuation is typically limited to a few kHz bandwidth when using step inputs due to its intrinsic thermal time constant. However, the use of pre-shaped input signals offers a route for reducing the rise time of these actuators by orders of magnitude. We started with an electrothermally actuated cantilever having an initial 10-90% rise time of 85 µs in air and 234 µs in water for a standard open-loop step input. We experimentally characterized the linearity and frequency response of the cantilever when operated in air and water, allowing us to obtain transfer functions for the two cases. We used these transfer functions, along with functions describing desired reduced rise-time system responses, to numerically simulate the required input signals. Using these pre-shaped input signals, we improved the open-loop 10-90% rise time from 85 µs to 3 µs in air and from 234 µs to 5 µs in water, an improvement by a factor of 28 and 47, respectively. Using this simple control strategy for MEMS electrothermal actuators makes them an attractive alternative to other high speed micromechanical actuators such as piezoelectric stacks or electrostatic comb structures which are more complex to design, fabricate, or operate.

Thermodynamic integration methods, infinite swapping, and the calculation of generalized averages.

In the present paper we examine the risk-sensitive and sampling issues associated with the problem of calculating generalized averages. By combining thermodynamic integration, stationary phase Monte Carlo, and infinite swapping techniques, we develop an approach for such problems and explore its utility for a prototypical class of applications.

[Diabetes mellitus as a prognostic marker in oropharyngeal and laryngeal squamous cell carcinoma]. / Diabetes mellitus als prognostischer Marker beim Oropharynx- und Larynxkarzinom.

Recent experimental and clinical studies have provided compelling evidence that diabetes mellitus (DM) is an important risk factor in various cancers, and may affect both pathogenesis and prognosis. Additionally, antidiabetic agents such as metformin exhibit an antitumorigenic effect. However, to date there is insufficient knowledge about the role of DM in the pathogenesis and prognosis of head and neck squamous cell carcinoma (HNSCC).In a retrospective monocentric study including 424 patients with SCC of the oropharynx (OPSCC) or larynx (LaSCC), the impact of DM on clinical and histopathologic parameters was investigated. The authors found a rising incidence of DM among LaSCC patients (<10 % until 2005 and 20 % since 2006) and a significant association between DM and clinical and histopathologic features (age, gender, tumor size, and pathologic grading), which depended on the anatomic site. Moreover, a clear trend toward unfavorable progression-free and overall survival of HNSCC patients with DM upon current treatment modalities was evident.The presented data support a relative increase in patients with DM, particularly for LaSCC. This might have a sustained influence on treatment decisions and management, and should be considered in future clinical trials. A better understanding of the cellular and molecular traits of HNSCC in DM could pave the way for innovative therapeutic strategies in terms of personalized medicine.

On performance measures for infinite swapping Monte Carlo methods.

We introduce and illustrate a number of performance measures for rare-event sampling methods. These measures are designed to be of use in a variety of expanded ensemble techniques including parallel tempering as well as infinite and partial infinite swapping approaches. Using a variety of selected applications, we address questions concerning the variation of sampling performance with respect to key computational ensemble parameters.

Scaling up conservation agriculture: An exploration of challenges and opportunities through a stakeholder engagement process.

Increasing the resilience of agricultural landscapes requires fundamental changes to the dominant commodity production model, including incorporating practices such as reduced tillage, cover cropping, and extended rotations that reduce soil disturbance while increasing biological diversity. Increasing farmer adoption of these conservation systems offers the potential to transform agriculture to a more vibrant, resilient system that protects soil, air, and water quality. Adoption of these resilience practices is not without significant challenges. This paper presents findings from a participatory effort to better understand these challenges and to develop solutions to help producers overcome them. Through repeated, facilitated discussions with farmers and agricultural and conservation professionals across the U.S. state of Michigan, we confronted the policy, economic, and structural barriers that are inhibiting broader adoption of conservation systems, as well as identified policies, programs, and markets that can support their adoption. What emerged was a complex picture and dynamic set of challenges at multiple spatial scales and across multiple domains. The primary themes emerging from these discussions were barriers and opportunities, including markets, social networks, human capital, and conservation programs. Exacerbating the technical, agronomic, and economic challenges farmers face at the farm level, there are a host of community constraints, market access and availability problems, climatic and environmental changes, and policies (governmental and corporate) that cross-pressure farmers when it comes to making conservation decisions. Understanding these constraints is critical to developing programs, policies, and state and national investments that can drive adoption of conservation agriculture.

[Treatment of unicompartmental osteoarthritis of the knee]. / Therapie der unikompartimentellen Gonarthrose.

Osteoarthritis of the knee is one of the most important degenerative joint diseases in the clinical routine. The treatment of knee osteoarthritis is not only based on the stage, symptoms and duration of the joint disease, but also depends on the existing arthrosis pattern. In the case of unicompartmental arthrosis, damage typical for osteoarthritis is limited to just one joint compartment. Both the conservative and the surgical treatment of unicompartmental osteoarthritis of the knee have to respect the individual characteristics of the respective forms of osteoarthritis. In the context of this manuscript, the genesis, the diagnostics and the guideline-based stage-adapted conservative and operative treatment of unicompartmental osteoarthritis of the knee are addressed.

Rare-event sampling: occupation-based performance measures for parallel tempering and infinite swapping Monte Carlo methods.

In the present paper we identify a rigorous property of a number of tempering-based Monte Carlo sampling methods, including parallel tempering as well as partial and infinite swapping. Based on this property we develop a variety of performance measures for such rare-event sampling methods that are broadly applicable, informative, and straightforward to implement. We illustrate the use of these performance measures with a series of applications involving the equilibrium properties of simple Lennard-Jones clusters, applications for which the performance levels of partial and infinite swapping approaches are found to be higher than those of conventional parallel tempering.

An infinite swapping approach to the rare-event sampling problem.

We describe a new approach to the rare-event Monte Carlo sampling problem. This technique utilizes a symmetrization strategy to create probability distributions that are more highly connected and, thus, more easily sampled than their original, potentially sparse counterparts. After discussing the formal outline of the approach and devising techniques for its practical implementation, we illustrate the utility of the technique with a series of numerical applications to Lennard-Jones clusters of varying complexity and rare-event character.

Finite-temperature quantum simulations of mixed rare gas clusters.

Finite-temperature quantum Monte Carlo simulations are presented for mixed neon/argon rare gas clusters containing up to n=10 atoms. For the smallest clusters (n=3) comparison with rigorous bound state calculations and experiments shows that the present approach is accurate to within fractions of wavenumbers for energies and to within a few percent or better for rotational constants. For larger cluster sizes, for which no rigorous quantum calculations are available, comparison with experiment becomes even more favorable. In all simulations accurate pair potentials for the rare gas-rare gas interactions are employed and comparison with high-level electronic structure calculations suggest that many-body interactions play a minor role. For the largest clusters investigated (Ne(4)Ar(6)) gradual melting of the neon phase is observed while the argon-phase remains structurally intact.

Spatial averaging for small molecule diffusion in condensed phase environments.

Spatial averaging is a new approach for sampling rare-event problems. The approach modifies the importance function which improves the sampling efficiency while keeping a defined relation to the original statistical distribution. In this work, spatial averaging is applied to multidimensional systems for typical problems arising in physical chemistry. They include (I) a CO molecule diffusing on an amorphous ice surface, (II) a hydrogen molecule probing favorable positions in amorphous ice, and (III) CO migration in myoglobin. The systems encompass a wide range of energy barriers and for all of them spatial averaging is found to outperform conventional Metropolis Monte Carlo. It is also found that optimal simulation parameters are surprisingly similar for the different systems studied, in particular, the radius of the point cloud over which the potential energy function is averaged. For H(2) diffusing in amorphous ice it is found that facile migration is possible which is in agreement with previous suggestions from experiment. The free energy barriers involved are typically lower than 1 kcal/mol. Spatial averaging simulations for CO in myoglobin are able to locate all currently characterized metastable states. Overall, it is found that spatial averaging considerably improves the sampling of configurational space.

Erratum to "Evaluation of MoPyC-prosthesis implantation and the use of angular stable plates in the treatment of comminuted radial head fractures" [J. Orthop. 16 (2019) 288-293].

[This corrects the article DOI: 10.1016/j.jor.2019.03.002.].

Randomly exact methods.

Important advances in the understanding of "random" processes have produced a variety of stochastic algorithms that offer unprecedented scope and utility in the study of physical systems. These algorithms represent a departure from the usual philosophy inherent in the study of many-body problems and have a number of significant features. Chief among these features are simplicity, weak dependence on dimensionality, and ease of transition between classical and quantum-mechanical descriptions. These methods are also readily adapted for use on massively paraliel computer architectures. These new stochastic methods represent a valuable addition to the tools available for the analysis of both equilibrium and time-dependent many-body problems.

The thermodynamic and ground state properties of the TIP4P water octamer.

Several stochastic simulations of the TIP4P [W. L. Jorgensen, J. Chandrasekhar, J. D. Madura, R. W. Impey, and M. L. Klein, J. Chem. Phys. 79, 926 (1983)] water octamer are performed. Use is made of the stereographic projection path integral and the Green's function stereographic projection diffusion Monte Carlo techniques, recently developed in one of our groups. The importance sampling for the diffusion Monte Carlo algorithm is obtained by optimizing a simple wave function using variational Monte Carlo enhanced with parallel tempering to overcome quasiergodicity problems. The quantum heat capacity of the TIP4P octamer contains a pronounced melting peak at 160 K, about 50 K lower than the classical melting peak. The zero point energy of the TIP4P water octamer is 0.0348+/-0.0002 hartree. By characterizing several large samples of configurations visited by both guided and unguided diffusion walks, we determine that both the TIP4P and the SPC [H. J. C. Berendsen, J. P. Postma, W. F. von Gunsteren, and J. Hermans, (Intermolecular Forces, Reidel, 1981). p. 331] octamer have a ground state wave functions predominantly contained within the D(2d) basin of attraction. This result contrasts with the structure of the global minimum for the TIP4P potential, which is an S(4) cube. Comparisons of the thermodynamic and ground-state properties are made with the SPC octamer as well.

The phenomenon of twisted growth: humeral torsion in dominant arms of high performance tennis players.

This manuscript is driven by the need to understand the fundamental mechanisms that cause twisted bone growth and shoulder pain in high performance tennis players. Our ultimate goal is to predict bone mass density in the humerus through computational analysis. The underlying study spans a unique four level complete analysis consisting of a high-speed video analysis, a musculoskeletal analysis, a finite element based density growth analysis and an X-ray based bone mass density analysis. For high performance tennis players, critical loads are postulated to occur during the serve. From high-speed video analyses, the serve phases of maximum external shoulder rotation and ball impact are identified as most critical loading situations for the humerus. The corresponding posts from the video analysis are reproduced with a musculoskeletal analysis tool to determine muscle attachment points, muscle force vectors and overall forces of relevant muscle groups. Collective representative muscle forces of the deltoid, latissimus dorsi, pectoralis major and triceps are then applied as external loads in a fully 3D finite element analysis. A problem specific nonlinear finite element based density analysis tool is developed to predict functional adaptation over time. The density profiles in response to the identified critical muscle forces during serve are qualitatively compared to X-ray based bone mass density analyses.

[Iatrogenic Cushing's syndrome, diabetes mellitus and secondary adrenal failure in a human immunodeficiency virus patient treated with ritonavir boosted atazanavir and fluticasone]. / Insuffisance surrénale aiguë chez un patient infecté par le virus d'immunodéficience humaine traité par atazanavir << boosté >> par ritonavir et fluticasone. Description d'un cas avec syndrome de Cushing associé chez un patient hospitalisé pour découverte d'un diabète.

Ritonavir and atazanavir (ATZ) are protease inhibitors (PI) that inhibit the P450 3A4 cytochrome. They are used together to boost ATZ levels and reduce pill burden in human immunodeficiency virus infection, but association with medications metabolized by this cytochrome can cause serious adverse effects. Several cases of Cushing's syndrome have been reported when patients received inhaled therapy with fluticasone for asthma, sometimes complicated by secondary adrenal failure after stopping fluticasone. We report a case of Cushing's syndrome associated with onset of diabetes mellitus in a patient treated with boosted PI (ATZ and ritonavir) for HIV 2 (CD4360/ml). Asthma was treated with inhaled fluticasone 1500mug/day for several months that was stopped at admission. A few days later, typical secondary adrenal failure developed and was confirmed by dosage of cortisol and ACTH, both low. Hydrocortisone replacement treatment resulted in rapid improvement of symptoms. Diabetes was initially treated with insulin then sulfonyluraes, but repeated hypoglycemias lead to diet alone. Physicians should be aware of the potential danger of the association of "boosted" IP and some kind of inhaled corticotherapy.

Evaluation of MoPyC-prosthesis implantation and the use of angular stable plates in the treatment of comminuted radial head fractures.

OBJECTIVE: Comminuted radial head fractures are disproportionately often accompanied by injuries of the bone or ligaments and can be treated in different ways. METHODS: 15 patients with a comminuted radial head fracture were treated with an angular stable plate (=G1) and 8 with a MoPyC-prosthesis (=G2). RESULTS: G1 shows an average Morrey-score of 83,87 points. Complications occurred in 5/15 patients. Within G2 an average Morrey-score of 86 was achieved. Complications could be shown in 2/8 patients. CONCLUSION: Both the treatment provides a clear individual benefit for the patients and predict promising results for the treatment of comminuted radial head fractures.

Evaluation of MoPyC-prosthesis implantation and the use of angular stable plates in the treatment of comminuted radial head fractures.

OBJECTIVE: Comminuted radial head fractures are disproportionately often accompanied by injuries of the bone or ligaments and can be treated in different ways. METHODS: 15 patients with a comminuted radial head fracture were treated with an angular stable plate (=G1) and 8 with a MoPyC-prosthesis (=G2). RESULTS: G1 shows an average Morrey-score of 83,87 points. Complications occurred in 5/15 patients. Within G2 an average Morrey-score of 86 was achieved. Complications could be shown in 2/8 patients. CONCLUSION: Both the treatment provides a clear individual benefit for the patients and predict promising results for the treatment of comminuted radial head fractures.

A stereographic projection path integral study of the coupling between the orientation and the bending degrees of freedom of water.

A Monte Carlo path integral method to study the coupling between the rotation and bending degrees of freedom for water is developed. It is demonstrated that soft internal degrees of freedom that are not stretching in nature can be mapped with stereographic projection coordinates. For water, the bending coordinate is orthogonal to the stereographic projection coordinates used to map its orientation. Methods are developed to compute the classical and quantum Jacobian terms so that the proper infinitely stiff spring constant limit is recovered in the classical limit, and so that the nonconstant nature of the Riemann Cartan curvature scalar is properly accounted in the quantum simulations. The theory is used to investigate the effects of the geometric coupling between the bending and the rotating degrees of freedom for the water monomer in an external field in the 250 to 500 K range. We detect no evidence of geometric coupling between the bending degree of freedom and the orientations.

Options and limits of angle stable plates in the treatment of comminuted radial head fractures.

OBJECTIVE: New angle-stable plates provide more stability and better anatomical fit than previous plates. METHODS: 22 patients treated with an angle-stable plate were included. Postoperative the outcomes were evaluated according to the scoring systems of Morrey, Radin and Riseborough. RESULTS: 3 patients received a score of excellent, 14 good, and 5 satisfactory. We detected 3 cases of implant failure and 2 cases of postoperative neurological damage. 3 patientes received a radial head necrosis. CONCLUSIONS: Our results show that the angle-stable radial head locking plate can only be used in limited cases in the treatment of multi-fragment radial head fractures.