Large Quantum Delocalization of a Levitated Nanoparticle Using Optimal Control: Applications for Force Sensing and Entangling via Weak Forces.

We propose to optimally control the harmonic potential of a levitated nanoparticle to quantum delocalize its center-of-mass motional state to a length scale orders of magnitude larger than the quantum zero-point motion. Using a bang-bang control of the harmonic potential, including the possibility of inverting it, the initial ground-state-cooled levitated nanoparticle coherently expands to large scales and then contracts to the initial state in a time-optimal way. We show that this fast loop protocol can be used to enhance force sensing as well as to dramatically boost the entangling rate of two weakly interacting nanoparticles. We parameterize the performance of the protocol, and therefore the macroscopic quantum regime that could be explored, as a function of displacement and frequency noise in the nanoparticle's center-of-mass motion. This noise analysis accounts for the sources of decoherence relevant to current experiments.

Orders of magnitude loss reduction in photonic bandgap fibers by engineering the core surround.

We demonstrate how to reduce the loss in photonic bandgap fibers by orders of magnitude by varying the radius of the corner strands in the core surround. As a fundamental working principle we find that changing the corner strand radius can lead to backscattering of light into the fiber core. Selecting an optimal corner strand radius can thus reduce the loss of the fundamental core mode in a specific wavelength range by almost two orders of magnitude when compared to an unmodified cladding structure. Using the optimal corner radius for each transmission window, we observe the low-loss behavior for the first and second bandgaps, with the losses in the second bandgap being even lower than that of the first one. Our approach of reducing the confinement loss is conceptually applicable to all kinds of photonic bandgap fibers including hollow core and all-glass fibers as well as on-chip light cages. Therefore, our concept paves the way to low-loss light guidance in such systems with substantially reduced fabrication complexity.

Human Inhalation Study with Zinc Oxide: Analysis of Zinc Levels and Biomarkers in Exhaled Breath Condensate.

Workers in the zinc processing, for example, welding or hot-dip galvanizing, are exposed to aerosols consisting of particles and gases, including zinc oxide (ZnO), which can affect human health. In this study, we addressed the effects of short-term controlled exposure to nano-sized ZnO on the airway inflammatory markers in healthy volunteers. To this end, we determined the influence of ZnO inhalation on the content of zinc and biomarkers (leukotriene B4 (LTB4), peptide leukotrienes (LTC4/D4/E4), 8-iso-PGF2α, pH, and prostaglandin E2 (PGE2)) in exhaled breath condensate (EBC). Sixteen non-smoking subjects (8 females, 8 men) were exposed to filtered air (sham) or ZnO nanoparticles (0.5, 1.0, and 2.0 mg/m3) for 4 h. EBC samples were collected according to specific study design. We found that the peptide leukotrienes were below the limit of quantification (LOQ) in all the EBC samples. ZnO exposure showed no detectable effect on any other parameters investigated when comparing the two groups. The content of Zn in EBC was unaffected by ZnO inhalation at any concentration used. Therefore, we conclude that the evaluation of Zn and biomarker content in EBC would not be a suitable way to assess the exposure to inhaled ZnO.

On the pole expansion of electromagnetic fields.

In several publications, it has been shown how to calculate the near- or far-field properties for a given source or incident field using the resonant states, also known as quasi-normal modes. As previously noted, this pole expansion is not unique, and there exist many equivalent formulations with dispersive expansion coefficients. Here, we approach the pole expansion of the electromagnetic fields using the Mittag-Leffler theorem and obtain another set of formulations with constant weight factors for each pole. We compare the performance and applicability of these formulations using analytical and numerical examples. It turns out that the accuracy of all approaches is rather comparable with a slightly better global convergence of the approach based on a formulation with dispersive expansion coefficients. However, other expansions can be superior locally and are typically faster. Our work will help with selecting appropriate formulations for an efficient description of the electromagnetic response in terms of the resonant states.

[Outpatient treatment of acute injuries of upper extremities with axillary plexus anesthesia in the emergency department-Is that possible without continuous anesthesia attendance?] / Ambulante Versorgung akuter Verletzungen der oberen Extremität in der Notfallambulanz in axillärer Plexusanästhesie ­ Ist das ohne durchgehende Anästhesiebegleitung machbar?

BACKGROUND: The incorporation into the routine operating procedure of patients with small but acute hand and forearm injuries requiring surgery who present in the emergency admission department, represents a challenge due to limited resources. The prompt treatment in the emergency admission department represents an alternative. This article retrospectively reports the authors' experiences with a treatment algorithm in which emergency patients were treated by ultrasound-guided axillary brachial plexus blocks (ABPB) and surgery carried out in the emergency department without further anesthesia attendance. METHODS: Patients were preselected by the surgeon if they were suitable for a standardized treatment without anesthesia attendance during surgery. If there were no anesthesiological or surgical contraindications patients received an ABPB in the holding area of the operating room (OR) under standard monitoring. Blocks were performed as a multi-injection, ultrasound-guided technique which is anatomically described in detail. Patients >60 kg received a total volume of 30 ml of a mixture of 10 ml 1% ropivacaine (100 mg) and 20 ml 2% prilocaine (400 mg). Patients <60 kg received the same mixture with a reduced volume of 25 ml corresponding to 82.5 mg ropivacaine and 332.5 mg prilocaine. After controlling for block success patients were admitted to the emergency department and the surgical procedure was carried out under supervision by the surgeon without further anesthesia attendance. At discharge patients were explicitly instructed that in the case of any complications or a continuation of the block for more than 24 h they should contact the emergency department. RESULTS: Between January 2013 and November 2017 a total of 566 patients (46.4 years, range 11-88 years, 174.9 cm, range 140-211cm, 80.8 kg, range 42-178kg, ASA 1/2/3, 190/338/38, respectively) were treated according to a standardized protocol. The ABPBs were performed by 74 anesthetists. In 5% of the patients the initial block was incomplete and rescue blocks were performed with a maximum of 2­3ml 1% prilocaine per corresponding nerve. After completion the block was ensured and all patients underwent surgery without further analgesics or local anesthetic infiltration by the surgeon. Complications related to the ABPB and readmissions were not observed. CONCLUSION: It could be demonstrated that minor surgery could be carried out safely and effectively with a defined algorithm using ABPB in selected patients outside the OR without permanent anesthesia attendance: however, indispensable prerequisites for such procedures are careful patient selection, patient compliance, the safe and effective performance of the ABPB and reliable agreement with the surgeon.

Recruitment and inclusion procedures as "pain killers" in clinical trials?

BACKGROUND: Recruitment and inclusion procedures in clinical trials are time critical. This holds particularly true for studies investigating patients with fluctuating symptom patterns, like those with chronic neck pain. In a feasibility study on neck pain, we found a clinically relevant decrease in pain ratings within the recruitment period. This paper analyses the phenomenon and gives recommendations for recruitment procedures in clinical trials on pain. METHODS: Changes in pain intensity scores of 44 chronic neck pain patients (6 males and 36 females; mean age: 45.3±13.2 years) between the first telephone contact and baseline assessment were analyzed. Inclusion criterion was a mean pain intensity of ≥40 on a 0-100 numerical rating scale during the last three months. Statistical analyses were performed using ANOVA and parametric/non-parametric correlation coefficients. RESULTS: Average pain intensity score decreased significantly from 60.3±13.3 at telephone interview to 38.1±21.7 at baseline assessment. This represents a relative change of 36.8%. A weak but significant negative correlation was found between number of days between assessments and pain rating differences. There was a positive correlation between change of pain intensity and the pain level at the first contact, indicating that the decreased pain ratings over time were also dependent on the initial pain rating. CONCLUSIONS: The clinically significant changes in pain intensity were weakly related to waiting time and moderately dependent on initial pain intensity, suggesting regression to the mean. The natural course of the disease and the Hawthorne effect are also discussed as contributing factors.

Quasinormal mode solvers for resonators with dispersive materials.

Optical resonators are widely used in modern photonics. Their spectral response and temporal dynamics are fundamentally driven by their natural resonances, the so-called quasinormal modes (QNMs), with complex frequencies. For optical resonators made of dispersive materials, the QNM computation requires solving a nonlinear eigenvalue problem. This raises a difficulty that is only scarcely documented in the literature. We review our recent efforts for implementing efficient and accurate QNM solvers for computing and normalizing the QNMs of micro- and nanoresonators made of highly dispersive materials. We benchmark several methods for three geometries, a two-dimensional plasmonic crystal, a two-dimensional metal grating, and a three-dimensional nanopatch antenna on a metal substrate, with the perspective to elaborate standards for the computation of resonance modes.

Quantum Calculations on Plant Cell Wall Component Interactions.

Density functional theory calculations were performed to assess the relative interaction energies of plant cell wall components: cellulose, xylan, lignin and pectin. Monomeric and tetramer linear molecules were allowed to interact in four different configurations for each pair of compounds. The M05-2X exchange-correlation functional which implicitly accounts for short- and mid-range dispersion was compared against MP2 and RI-MP2 to assess the reliability of the former for modeling van der Waals forces between these PCW components. Solvation effects were examined by modeling the interactions in the gas phase, in explicit H2O, and in polarized continuum models (PCM) of solvation. PCMs were used to represent water, methanol, and chloroform. The results predict the relative ranges of each type of interaction and when specific configurations will be strongly preferred. Structures and energies are useful as a basis for testing classical force fields and as guidance for coarse-grained models of PCWs.

First-order perturbation theory for changes in the surrounding of open optical resonators.

The single-mode approximation of resonant state expansion has proven to give accurate first-order approximations of resonance shifts and linewidth changes when modifying the material properties inside open optical resonators. Here, we extend this first-order perturbation theory to modifications of the material properties in the surrounding medium. As a side product of our derivations, we retrieve the already known analytical normalization condition for resonant states. We apply our theory to two example systems: a metallic nanosphere and a periodic array of metallic nanoslits.

Analytic Mode Normalization for the Kerr Nonlinearity Parameter: Prediction of Nonlinear Gain for Leaky Modes.

Based on the resonant-state expansion with analytic mode normalization, we derive a general master equation for the nonlinear pulse propagation in waveguide geometries that is valid for bound and leaky modes. In the single-mode approximation, this equation transforms into the well-known nonlinear Schrödinger equation with a closed expression for the Kerr nonlinearity parameter. The expression for the Kerr nonlinearity parameter can be calculated on the minimal spatial domain that spans only across the regions of spatial inhomogeneities. It agrees with previous vectorial formulations for bound modes, while for leaky modes the Kerr nonlinearity parameter turns out to be a complex number with the imaginary part providing either nonlinear loss or even gain for the overall attenuating pulses. This nonlinear gain results in more intense pulse compression and stronger spectral broadening, which is demonstrated here on the example of liquid-filled capillary-type fibers.

Relieving phantom limb pain with multimodal sensory-motor training.

OBJECTIVE: The causes for the disabling condition of phantom limb pain (PLP), affecting 85% of amputees, are so far unknown, with few effective treatments available. Sensory feedback based strategies to normalize the motor commands to control the phantom limb offer important targets for new effective treatments as the correlation between phantom limb motor control and sensory feedback from the motor intention has been identified as a possible mechanism for PLP development. APPROACH: Ten upper-limb amputees, suffering from chronic PLP, underwent 16 days of intensive training on phantom-limb movement control. Visual and tactile feedback, driven by muscular activity at the stump, was provided with the aim of reducing PLP intensity. MAIN RESULTS: A 32.1% reduction of PLP intensity was obtained at the follow-up (6 weeks after the end of the training, with an initial 21.6% reduction immediately at the end of the training) reaching clinical effectiveness for chronic pain reduction. Multimodal sensory-motor training on phantom-limb movements with visual and tactile feedback is a new method for PLP reduction. SIGNIFICANCE: The study results revealed a substantial reduction in phantom limb pain intensity, obtained with a new training protocol focused on improving phantom limb motor output using visual and tactile feedback from the stump muscular activity executed to move the phantom limb.

Analytical mode normalization and resonant state expansion for bound and leaky modes in optical fibers - an efficient tool to model transverse disorder.

We adapt the resonant state expansion to optical fibers such as capillary and photonic crystal fibers. As a key requirement of the resonant state expansion and any related perturbative approach, we derive the correct analytical normalization for all modes of these fiber structures, including leaky modes that radiate energy perpendicular to the direction of propagation and have fields that grow with distance from the fiber core. Based on the normalized fiber modes, an eigenvalue equation is derived that allows for calculating the influence of small and large perturbations such as structural disorder on the guiding properties. This is demonstrated for two test systems: a capillary fiber and a photonic crystal fiber.

Modeling of second-harmonic generation in periodic nanostructures by the Fourier modal method with matched coordinates.

We present an advanced formulation of the Fourier modal method for analyzing the second-harmonic generation in multilayers of periodic arrays of nanostructures. In our method, we solve Maxwell's equations in a curvilinear coordinate system, in which the interfaces are defined by surfaces of constant coordinates. Thus, we can apply the correct Fourier factorization rules as well as adaptive spatial resolution to nanostructures with complex cross sections. We extend here the factorization rules to the second-harmonic susceptibility tensor expressed in the curvilinear coordinates. The combination of adaptive curvilinear coordinates and factorization rules allows for efficient calculation of the second-harmonic intensity, as demonstrated for one- and two-dimensional periodic nanostructures.

Resonant-state expansion for open optical systems: generalization to magnetic, chiral, and bi-anisotropic materials.

The resonant-state expansion, a recently developed powerful method in electrodynamics, is generalized here for open optical systems containing magnetic, chiral, or bi-anisotropic materials. It is shown that the key matrix eigenvalue equation of the method remains the same, but the matrix elements of the perturbation now contain variations of the permittivity, permeability, and bi-anisotropy tensors. A general normalization of resonant states in terms of the electric and magnetic fields is presented.

[Basic principles of diagnosis and treatment of gliomas]. / Grundlagen zur Diagnose und Therapie von Gliomen.

BACKGROUND: Traditionally, gliomas were classified based on histopathological features alone. The revised World Health Organization (WHO) classification of tumors of the central nervous system from 2016 integrated molecular features into the histopathological diagnosis. OBJECTIVE: To summarize key aspects of the WHO classification from 2016 and implications for the clinical management of glioma patients. An overview of novel treatment approaches is also provided. RESULTS: Oligodendrogliomas are defined independently of their histopathological appearance by the simultaneous presence of a mutation in the isocitrate dehydrogenase (IDH)-1 or IDH-2 gene and co-deletion of chromosome arms 1p and 19q. Astrocytomas are classified based on the presence or absence of mutations in IDH. Astrocytic tumors with wild-type IDH comprise approximately 90% of glioblastomas, the most common malignant primary brain tumor in adults. The extent of resection is a favorable prognostic factor in diffuse gliomas. Postoperatively, most patients are treated with a combination of radiotherapy and alkylating agent chemotherapy. In IDH wild-type astrocytic tumors, hypermethylation of the promoter of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) gene is predictive for benefit from the alkylating agent temozolomide. Most novel treatment approaches that are currently being assessed in clinical trials aim at reprogramming the immune system to specifically eradicate tumor cells, but the efficacy of such approaches in gliomas remains to be demonstrated. DISCUSSION: To date the classical treatment modalities comprising surgery, radiotherapy and chemotherapy remain the mainstay of glioma treatment. The integration of molecular features into the classification of gliomas is a basis for personalized treatment approaches.

Chronic intensive care-related pain: Exploratory analysis on predictors and influence on health-related quality of life.

BACKGROUND: There is growing evidence for the development of chronic pain after intensive care. Nonetheless, there is only limited knowledge about factors leading to chronic intensive care-related pain (CIRP). Thus, the primary objective was the identification of predictors of CIRP. Moreover, we aimed to assess the impact of CIRP on patients' health-related quality of Life (HRQOL). METHODS: Comprehensive information on patients' pain before ICU admission and present pain was collected longitudinally by means of the German Pain Questionnaire 6 and 12 months after ICU discharge (ICUDC ). In addition, a subsample of patients underwent Quantitative Sensory Testing (QST). We used Generalized Estimating Equations to identify predictors of CIRP with logistic regression models. RESULTS: In total, 204 patients (197/159 at 6/12 months after ICUDC ) were available for the analyses. In the multivariate models, moderate to severe average pain in the 4 weeks after ICUDC , lower age, female sex, increased inflammation and chronic pain conditions and increased levels of anxiety before ICU admission were predictive for CIRP. In addition, small fibre deficits and lower disease severity were associated with CIRP in the QST subsample (81 patients, 77/55 at 6/12 months after ICUDC ). Patients with CIRP reported significantly lower HRQOL than patients without CIRP. CONCLUSIONS: Chronic intensive care-related pain is associated with specific decrements in HRQOL. Knowledge about the identified predictors is of clinical and scientific importance and might help to reduce the incidence of CIRP. SIGNIFICANCE: Chronic intensive care-related pain is associated with specific decrements in health-related quality of life. While most of the identified predictors for CIRP can only be considered as risk factors, especially adequate (post-) acute pain management should be studied as preventive strategy.

Percutaneous vertebral augmentation in fragility fractures-indications and limitations.

INTRODUCTION: There is still no general consensus about the management of osteoporotic vertebral fractures. Recommendations depend on type of fracture, grade of instability, bone quality, and general conditions of the patient. Spontaneous fractures may be considered to be treated different compared to cases with high-velocity trauma. METHODS: According to the DVO, patients without trauma should first be treated conservatively. However, there is no more strict time protocol of 3 or 6 week conservative treatment before operations may be indicated. Surgical criteria are not yet distinctly defined. For highly unstable fractures (type B and C according to the AO Spine Classification), posterior instrumentation with cement augmented screws and as long construct, respectively, is adequate. Current literature has been analysed for diagnostic and therapeutic protocols. RESULTS: There is no clear operative concept for burst fractures and classic osteoporotic fractures with dynamic ongoing sintering. Percutaneous vertebral augmentation showed to prevent the fractures from ongoing kyphotic deformity and the patients from painful immobilization. Indications and results of classical vertebroplasty and kyphoplasty have been discussed intensively in the literature. Further development included special injection techniques, cements with different viscosities and stenting systems to reach more stable constructs and avoid typical complications, such as cement extrusion. CONCLUSIONS: This review reports upon indications and limitations of percutaneous vertebral augmentation and the potential development of classifications and therapeutic algorithms.