Most wind turbines are remotely monitored 24/7 to allow for an early detection of operation problems and developing damage. We present a new fault detection method for vibration-monitored drivetrains ...that does not require any feature engineering. Our method relies on a simple model architecture to enable a straightforward implementation in practice. We propose to apply convolutional autoencoders for identifying and extracting the most relevant features from the half spectrum in an automated manner, saving time and effort. Thereby, a spectral model of the normal vibration response is learnt for the monitored component from past measurements. We demonstrate that the model can successfully distinguish damaged from healthy components and detect a damaged generator bearing and damaged gearbox parts from their vibration responses. Using measurements from commercial wind turbines and a test rig, we show that vibration-based fault detection in wind turbine drivetrains can be performed without the usual upfront definition of spectral features. Another advantage of the presented method is that the entire half spectrum is monitored instead of the usual focus on monitoring individual frequencies and harmonics.
Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS) is a novel 2-stage technique intended to induce rapid growth of the future liver remnant(FLR). Initial reports of a ...12% mortality rate have sparked debate regarding the safety of the procedure. A 64 years old male was planned for a rightsided hemi-hepatectomy due to colorectal cancer liver metastases. Intra-operatively it was decided to convert to an ALPPS due to unexpectedly small segments 2-4. Post-operative serum laboratory tests indicated an acute liver failure and radiological imaging showed no sign of arterial blood flow to the right hemi-liver. A computed tomography examination on post-operative day 3 revealed that the FLR had increased from 290 to 690 m L in 3 d(138% growth). In the following days serum values gradually improved and stage 2 was carried out on post-operative day 7. The rest of the hospital stay was uneventful and the patient made a full recovery. ALPPS is a fascinating advancement in liver surgery. Despite severe post-operative complications, in properly selected cases it provides successful outcomes that other modalities of treatment cannot offer.
Internationale Gesundheitssysteme im Vergleich Jonas Trambacz, Angelika Wehage, Stefan Schmeier, Seray Röblreiter, Christof Mauersberg, Christian Döhmen, Phillis Maaß, Adrian Borner
2015
eBook
Nahezu alle Gesundheitssysteme westlich-orientierter Länder stehen vor ähnlichen Herausforderungen und Schwierigkeiten. Das demographische Problem führt zu einer erhöhten Nachfrage nach ...Gesundheitsleistungen. Demgegenüber steht eine erniedrigte Einnahmesituation (gesundheitsökonomisches Fundamentalproblem). Ärztliches und pflegerisches Personal stoßen in Krankenhäusern an ihre Belastungsgrenzen. In ländlichen Regionen können Ärzte gänzlich fehlen. Da lohnt sich der Blick über den Tellerrand hinaus auf die Gesundheitssysteme anderer Nationen. Dabei können diese Vergleiche zeigen, welche Reformvorschläge bereits gemacht wurden und mit welchen Ergebnissen. Beispielhaft kann an dieser Stelle die Implementierung von Disease-Management- Programmen (DMP) in Deutschland benannt werden.In der vorliegenden Studie werden die Gesundheitssysteme von Singapur, den Niederlanden, Norwegen, der Schweiz, Japan, Frankreich, den USA und Österreich analysiert. Grundlage der Analyse sind die durch Claus Wendt benannten Dimensionen Finanzierung, Leistungserbringung und Regulierung. Jedem Gesundheitssystem wird ein Kapitel gewidmet. Jedes Kapitel endet mit einem Fazit, in dem es nach den Dimensionen klassifiziert wird. In Anschluss an die Analyse der Gesundheitssysteme unterstreicht ein Kennzahlenvergleich die Analyse der Gesundheitssysteme.
High-index dielectric metasurfaces featuring Mie-type electric and magnetic resonances have been of great interest in a variety of applications such as imaging, sensing, photovoltaics, and others, ...which led to the necessity of an efficient large-scale fabrication technique. To address this, here we demonstrate the use of single-pulse laser interference for direct patterning of an amorphous silicon film into an array of Mie resonators a few hundred nanometers in diameter. The proposed technique is based on laser-interference-induced dewetting. A precise control of the laser pulse energy enables the fabrication of ordered dielectric metasurfaces in areas spanning tens of micrometers and consisting of thousands of hemispherical nanoparticles with a single laser shot. The fabricated nanoparticles exhibit a wavelength-dependent optical response with a strong electric dipole signature. Variation of the predeposited silicon film thickness allows tailoring of the resonances in the targeted visible and infrared spectral ranges. Such direct and high-throughput fabrication is a step toward a simple realization of spatially invariant metasurface-based devices.
Machine learning potentials have become an important tool for atomistic simulations in many fields, from chemistry via molecular biology to materials science. Most of the established methods, ...however, rely on local properties and are thus unable to take global changes in the electronic structure into account, which result from long-range charge transfer or different charge states. In this work we overcome this limitation by introducing a fourth-generation high-dimensional neural network potential that combines a charge equilibration scheme employing environment-dependent atomic electronegativities with accurate atomic energies. The method, which is able to correctly describe global charge distributions in arbitrary systems, yields much improved energies and substantially extends the applicability of modern machine learning potentials. This is demonstrated for a series of systems representing typical scenarios in chemistry and materials science that are incorrectly described by current methods, while the fourth-generation neural network potential is in excellent agreement with electronic structure calculations.
Coding variants in the triggering receptor expressed on myeloid cells 2 (TREM2) are associated with late-onset Alzheimer's disease (AD). We demonstrate that amyloid plaque seeding is increased in the ...absence of functional Trem2. Increased seeding is accompanied by decreased microglial clustering around newly seeded plaques and reduced plaque-associated apolipoprotein E (ApoE). Reduced ApoE deposition in plaques is also observed in brains of AD patients carrying TREM2 coding variants. Proteomic analyses and microglia depletion experiments revealed microglia as one origin of plaque-associated ApoE. Longitudinal amyloid small animal positron emission tomography demonstrates accelerated amyloidogenesis in Trem2 loss-of-function mutants at early stages, which progressed at a lower rate with aging. These findings suggest that in the absence of functional Trem2, early amyloidogenesis is accelerated due to reduced phagocytic clearance of amyloid seeds despite reduced plaque-associated ApoE.
Digital color imaging relies on spectral filters on top of a pixelated sensor, such as a CMOS image sensor. An important parameter of imaging devices is their resolution, which depends on the size of ...the pixels. For many applications, a high resolution is desirable, consequently requiring small spectral filters. Dielectric nanostructures, due to their resonant behavior and its tunability, offer the possibility to be assembled into flexible and miniature spectral filters, which could potentially replace conventional pigmented and dye-based color filters. In this paper, we demonstrate the generation of transmissive structural colors based on uniform-height amorphous silicon nanostructures. We optimize the structures for the primary RGB colors and report the construction of submicrometer RGB filter arrays for a pixel size down to 0.5 μm.
Conspectus The development of first-principles-quality machine learning potentials (MLP) has seen tremendous progress, now enabling computer simulations of complex systems for which sufficiently ...accurate interatomic potentials have not been available. These advances and the increasing use of MLPs for more and more diverse systems gave rise to new questions regarding their applicability and limitations, which has constantly driven new developments. The resulting MLPs can be classified into several generations depending on the types of systems they are able to describe. First-generation MLPs, as introduced 25 years ago, have been applicable to low-dimensional systems such as small molecules. MLPs became a practical tool for complex systems in chemistry and materials science with the introduction of high-dimensional neural network potentials (HDNNP) in 2007, which represented the first MLP of the second generation. Second-generation MLPs are based on the concept of locality and express the total energy as a sum of environment-dependent atomic energies, which allows applications to very large systems containing thousands of atoms with linearly scaling computational costs. Since second-generation MLPs do not consider interactions beyond the local chemical environments, a natural extension has been the inclusion of long-range interactions without truncation, mainly electrostatics, employing environment-dependent charges establishing the third MLP generation. A variety of second- and, to some extent, also third-generation MLPs are currently the standard methods in ML-based atomistic simulations. In spite of countless successful applications, in recent years it has been recognized that the accuracy of MLPs relying on local atomic energies and charges is still insufficient for systems with long-ranged dependencies in the electronic structure. These can, for instance, result from nonlocal charge transfer or ionization and are omnipresent in many important types of systems and chemical processes such as the protonation and deprotonation of organic and biomolecules, redox reactions, and defects and doping in materials. In all of these situations, small local modifications can change the system globally, resulting in different equilibrium structures, charge distributions, and reactivity. These phenomena cannot be captured by second- and third-generation MLPs. Consequently, the inclusion of nonlocal phenomena has been identified as a next key step in the development of a new fourth generation of MLPs. While a first fourth-generation MLP, the charge equilibration neural network technique (CENT), was introduced in 2015, only very recently have a range of new general-purpose methods applicable to a broad range of physical scenarios emerged. In this Account, we show how fourth-generation HDNNPs can be obtained by combining the concepts of CENT and second-generation HDNNPs. These new MLPs allow for a highly accurate description of systems where nonlocal charge transfer is important.
Significance The study of membrane proteins is often hampered by their tendency to misfold when extracted by detergent. Here, we explore a detergent-free approach to isolating membrane proteins while ...retaining their native lipid environment, making use of an amphipathic polymer that solubilizes intact membrane patches in the form of nanodiscs. Using a potassium channel as a model protein, we show that these “native nanodiscs” are highly thermostable particles that are suitable for spectroscopic studies, allowing structural characterization of the protein in its native environment and direct analysis of the lipids in its immediate surroundings. We also demonstrate that the channel can be reconstituted from nanodiscs into planar lipid bilayers for functional characterization, thus making native nanodiscs an excellent alternative to detergent solubilization.
A major obstacle in the study of membrane proteins is their solubilization in a stable and active conformation when using detergents. Here, we explored a detergent-free approach to isolating the tetrameric potassium channel KcsA directly from the membrane of Escherichia coli , using a styrene-maleic acid copolymer. This polymer self-inserts into membranes and is capable of extracting membrane patches in the form of nanosize discoidal proteolipid particles or “native nanodiscs.” Using circular dichroism and tryptophan fluorescence spectroscopy, we show that the conformation of KcsA in native nanodiscs is very similar to that in detergent micelles, but that the thermal stability of the protein is higher in the nanodiscs. Furthermore, as a promising new application, we show that quantitative analysis of the co-isolated lipids in purified KcsA-containing nanodiscs allows determination of preferential lipid–protein interactions. Thin-layer chromatography experiments revealed an enrichment of the anionic lipids cardiolipin and phosphatidylglycerol, indicating their close proximity to the channel in biological membranes and supporting their functional relevance. Finally, we demonstrate that KcsA can be reconstituted into planar lipid bilayers directly from native nanodiscs, which enables functional characterization of the channel by electrophysiology without first depriving the protein of its native environment. Together, these findings highlight the potential of the use of native nanodiscs as a tool in the study of ion channels, and of membrane proteins in general.
Incipient ferroelectricity is known to occur in perovskites such as SrTiO3, KTaO3, and CaTiO3. For the first time it is shown that the intensively researched HfO2 thin films (16 nm) also possess ...ferroelectric properties when aluminium is incorporated into the host lattice. Polarization measurements on Al:HfO2 based metal–insulator–metal capacitors show an antiferroelectric‐to‐ferroelectric phase transition depending on annealing conditions and aluminium content. Structural investigation of the electrically characterized capacitors by grazing incidence X‐ray diffraction is presented in order to gain further insight on the potential origin of ferroelectricity. The non‐centrosymmetry of the elementary cell, which is essential for ferroelectricity, is assumed to originate from an orthorhombic phase of space group Pbc21 stabilized for low Al doping in HfO2. The ferroelectric properties of the modified HfO2 thin films yield high potential for various ferroelectric, piezoelectric, and pyroelectric applications. Furthermore, due to the extensive knowledge accumulated by various research groups regarding the HfO2 dielectric, an immediate relevance of ferroelectric hafnium oxide thin films is anticipated by the authors.
Polarization measurements show antiferroelectric‐to‐ferroelectric transitions in 16 nm thin film capacitors depending on annealing conditions and the molar concentration of incorporated aluminium. The ferroelectricity is attributed to a centrosymmetric to non‐centrosymmetric phase transition with decreasing aluminium content in the HfO2 host lattice. The incipient ferroelectric properties of the investigated material system hold the potential for various ferroelectric, piezoelectric, and semiconductor applications.
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