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Der Gesetzgeber hat kürzlich eine Änderung des Rechts der AGB beschlossen. Diese hat für Arbeitgeber zur Folge, dass sie ihre Muster-Arbeitsverträge anpassen müssen, wenn sie andernfalls drohende wirtschaftliche Nachteile vermeiden wollen. Mit Wirkung zum 1.10.2016 hat der Gesetzgeber § 309 Nr. 13 BGB neu gefasst. Nach der bisherigen Fassung waren vorformulierte Vertragsbedingungen unwirksam, die Anzeigen oder Erklärungen gegenüber dem Vertragspartner an „eine strengere Form als die Schriftform“ banden. Seit dem 1.10.2016 sind vorformulierte Vertragsbedingungen unwirksam, die derartige Anzeigen oder Erklärungen an „eine strengere Form als die Textform“ binden. Diese gesetzliche Neuregelung wirkt sich maßgeblich auf die Gestaltung von Arbeitsverträgen aus. Dies betrifft insbesondere die in Arbeitsverträgen gebräuchlichen Ausschlussfristen.
Nach jahrelangem Ringen haben sich die zuständigen Institutionen der EU auf ein einheitliches Datenschutzgesetz, die Datenschutz-Grundverordnung (DS-GV), geeinigt. Diese ist am 25.5.2016 in Kraft getreten und wird nach einer zweijährigen Übergangszeit am 25.5.2018 für alle EU-Mitgliedstaaten unmittelbar verbindlich. Verstöße hiergegen können erhebliche Sanktionen nach sich ziehen. Es drohen Bußgelder von bis zu 20 Mio. € oder bis zu 4 % des gruppenweiten Jahresumsatzes – je nachdem, welcher Betrag höher ist. Die betriebliche Praxis tut also gut daran, sich rechtzeitig mit den neuen Anforderungen zu befassen und diese umzusetzen. Dieser Beitrag gibt einen ersten Überblick über die sich aus der DS-GV ergebenden Konsequenzen für die betriebliche Praxis im Allgemeinen sowie im Hinblick auf die Datenverarbeitung im Beschäftigungskontext im Besonderen.
Kaum ein anderer Begriff hält so viele Varianten und Facetten bereit wie die Arbeitszeit. Für die betriebliche Praxis stellt sich dabei regelmäßig die Frage, was überhaupt zur Arbeitszeit gehört, entsprechend als solche zu vergüten ist und welche Optionen bei der Gestaltung der Arbeitsverträge bestehen. Der folgende Praxisleitfaden gibt einen Überblick über die aktuelle Rechtslage und enthält zugleich Hinweise für die Vertragsgestaltung. Die hierzu insbesondere in den letzten Jahren ergangenen zahlreichen aktuellen Gerichtsentscheidungen werden besonders berücksichtigt.
Das Bundeskabinett hat sich am 14.9.2016 mit der sog. Flexi-Rente befasst und eine sog. Formulierungshilfe verabschiedet, der ein aus den Regierungsfraktionen des Bundestages einzubringender entsprechender Gesetzesentwurf zur „Flexibilisierung des Übergangs vom Erwerbsleben in den Ruhestand und zur Stärkung von Prävention und Rehabilitation im Erwerbsleben (Flexirentengesetz)“ folgen soll. Eine entsprechende Vorabfassung des Gesetzesentwurfs liegt bereits vor (BT-Drucks. 18/9787). Mit der Flexi-Rente sollen im Wesentlichen zwei Ziele erreicht werden: Das flexible Arbeiten bis zum Erreichen der Regelaltersgrenze soll gefördert und das Weiterarbeiten über die Regelaltersgrenze hinaus attraktiver gemacht werden. Hierfür ist eine Reihe von gesetzlichen Änderungen geplant, insbesondere im SGB VI und SGB III. Teile des Gesetzes sollen schon zum 1.1.2017 in Kraft treten. Grund genug, sich bereits jetzt einen ersten Überblick über die geplanten Neuerungen zu verschaffen.
Replacement tissues, designed to fill in articular cartilage defects, should exhibit the same properties as the native material. The aim of this study is to foster the understanding of, firstly, the mechanical behavior of the material itself and, secondly, the influence of cultivation parameters on cell seeded implants as well as on cell migration into acellular implants. In this study, acellular cartilage replacement material is theoretically, numerically and experimentally investigated regarding its viscoelastic properties, where a phenomenological model for practical applications is developed. Furthermore, remodeling and cell migration are investigated.
We investigate the suitability of selected measures of complexity based on recurrence quantification analysis and recurrence networks for an identification of pre-seizure states in multi-day, multi-channel, invasive electroencephalographic recordings from five epilepsy patients. We employ several statistical techniques to avoid spurious findings due to various influencing factors and due to multiple comparisons and observe precursory structures in three patients. Our findings indicate a high congruence among measures in identifying seizure precursors and emphasize the current notion of seizure generation in large-scale epileptic networks. A final judgment of the suitability for field studies, however, requires evaluation on a larger database.
Wind-induced operational variability is one of the major challenges for structural health monitoring of slender engineering structures like aircraft wings or wind turbine blades. Damage sensitive features often show an even bigger sensitivity to operational variability. In this study a composite cantilever was subjected to multiple mass configurations, velocities and angles of attack in a controlled wind tunnel environment. A small-scale impact damage was introduced to the specimen and the structural response measurements were repeated. The proposed damage detection methodology is based on automated operational modal analysis. A novel baseline preparation procedure is described that reduces the amount of user interaction to the provision of a single consistency threshold. The procedure starts with an indeterminate number of operational modal analysis identifications from a large number of datasets and returns a complete baseline matrix of natural frequencies and damping ratios that is suitable for subsequent anomaly detection. Mahalanobis distance-based anomaly detection is then applied to successfully detect the damage under varying severities of operational variability and with various degrees of knowledge about the present operational conditions. The damage detection capabilities of the proposed methodology were found to be excellent under varying velocities and angles of attack. Damage detection was less successful under joint mass and wind variability but could be significantly improved through the provision of the currently encountered operational conditions.
Operational Modal Analysis (OMA) is a promising candidate for flutter testing and Structural Health Monitoring (SHM) of aircraft wings that are passively excited by wind loads. However, no studies have been published where OMA is tested in transonic flows, which is the dominant condition for large civil aircraft and is characterized by complex and unique aerodynamic phenomena. We use data from the HIRENASD large-scale wind tunnel experiment to automatically extract modal parameters from an ambiently excited wing operated in the transonic regime using two OMA methods: Stochastic Subspace Identification (SSI) and Frequency Domain Decomposition (FDD). The system response is evaluated based on accelerometer measurements. The excitation is investigated from surface pressure measurements. The forcing function is shown to be non-white, non-stationary and contaminated by narrow-banded transonic disturbances. All these properties violate fundamental OMA assumptions about the forcing function. Despite this, all physical modes in the investigated frequency range were successfully identified, and in addition transonic pressure waves were identified as physical modes as well. The SSI method showed superior identification capabilities for the investigated case. The investigation shows that complex transonic flows can interfere with OMA. This can make existing approaches for modal tracking unsuitable for their application to aircraft wings operated in the transonic flight regime. Approaches to separate the true physical modes from the transonic disturbances are discussed.
A refined substructure technique in the frequency domain is developed, which permits consideration of the interaction effects among adjacent containers through the supporting deformable soil medium. The tank-liquid systems are represented by means of mechanical models, whereas discrete springs and dashpots stand for the soil beneath the foundations. The proposed model is employed to assess the responses of adjacent circular, cylindrical tanks for harmonic and seismic excitations over wide range of tank proportions and soil conditions. The influence of the number, spatial arrangement of the containers and their distance on the overall system's behavior is addressed. The results indicate that the cross-interaction effects can substantially alter the impulsive components of response of each individual element in a tank farm. The degree of this impact is primarily controlled by the tank proportions and the proximity of the predominant natural frequencies of the shell-liquid-soil systems and the input seismic motion. The group effects should be not a priori disregarded, unless the tanks are founded on shallow soil deposit overlying very stiff material or bedrock.
In this study, we show that synthetic sapphire (Al₂O₃), an established implant material, can also serve as a platform material for biosensors comparable to nanocrystalline diamond. Sapphire chips, beads, and powder were first modified with (3-aminopropyl) triethoxysilane (APTES), followed by succinic anhydride (SA), and finally single-stranded probe DNA was EDC coupled to the functionalized layer. The presence of the APTES-SA layer on sapphire powders was confirmed by thermogravimetric analyis and Fourier-transform infrared spectroscopy. Using planar sapphire chips as substrates and X-ray photoelectron spectroscopy (XPS) as surface-sensitive tool, the sequence of individual layers was analyzed with respect to their chemical state, enabling the quantification of areal densities of the involved molecular units. Fluorescence microscopy was used to demonstrate the hybridization of fluorescently tagged target DNA to the probe DNA, including denaturation- and re-hybridization experiments. Due to its high thermal conductivity, synthetic sapphire is especially suitable as a chip material for the heat-transfer method, which was employed to distinguish complementary- and non-complementary DNA duplexes containing single-nucleotide polymorphisms. These results indicate that it is possible to detect mutations electronically with a chemically resilient and electrically insulating chip material.
An amperometric biosensor using a substrate recycling principle was realized for the detection of low adrenaline concentrations (1 nM) by measurements in phosphate buffer and Ringer’s solution at pH 6.5 and pH 7.4, respectively. In proof-of-concept experiments, a Boolean logic-gate principle has been applied to develop a digital adrenaline biosensor based on an enzyme AND logic gate. The obtained results demonstrate that the developed digital biosensor is capable for a rapid qualitative determination of the presence/absence of adrenaline in a YES/NO statement. Such digital biosensor could be used in clinical diagnostics for the control of a correct insertion of a catheter in the adrenal veins during adrenal venous-sampling procedure.
Visualization of the recovery process of defects in a cultured cell layer by chemical imaging sensor
(2016)
The chemical imaging sensor is a field-effect sensor which is able to visualize both the distribution of ions (in LAPS mode) and the distribution of impedance (in SPIM mode) in the sample. In this study, a novel cell assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the recovery of defects in a cell layer brought into proximity of the sensing surface. A reduced impedance at a defect formed artificially in a cell layer was successfully visualized in a photocurrent image. The cell layer was cultured over two weeks, during which the temporal change of the photocurrent distribution corresponding to the recovery of the defect was observed.
Light-addressable potentiometric sensor as a sensing element in plug-based microfluidic devices
(2016)
A plug-based microfluidic system based on the principle of the light-addressable potentiometric sensor (LAPS) is proposed. The LAPS is a semiconductor-based chemical sensor, which has a free addressability of the measurement point on the sensing surface. By combining a microfluidic device and LAPS, ion sensing can be performed anywhere inside the microfluidic channel. In this study, the sample solution to be measured was introduced into the channel in a form of a plug with a volume in the range of microliters. Taking advantage of the light-addressability, the position of the plug could be monitored and pneumatically controlled. With the developed system, the pH value of a plug with a volume down to 400 nL could be measured. As an example of plug-based operation, two plugs were merged in the channel, and the pH change was detected by differential measurement.
Insolvenzanfechtung: Keine Gläubigerbenachteiligung bei Ablösezahlung gegen Forderungsverzicht
(2016)
Schwerpunkt einer vorinsolvenzlichen Sanierung ist i.d.R., dass einzelne Gläubiger gegen Teilzahlungen auf ihre Forderungen verzichten und somit dem Unternehmen den notwendigen finanziellen Freiraum für einen Turnaround geben. Die Motivation der Gläubiger für einen Verzicht ist dabei auch die Überlegung, dass eine quotale Befriedigung im Rahmen eines Insolvenzverfahrens oft wesentlich geringer ausfallen würde als die durch den Vergleich realisierte Teilzahlung. Das Risiko, im Falle der Insolvenz eine Teilzahlung im Rahmen der Insolvenzanfechtung aber wieder zurückgewähren zu müssen, macht einen Forderungsverzicht weniger attraktiv. Mit Urteil vom 28.01.2016 hat der BGH nun entschieden, dass eine Insolvenzanfechtung mangels Gläubigerbenachteiligung ausscheidet, wenn der in der Teilzahlung liegende Vermögensverlust durch den damit verbundenen Verzicht auf die Restforderung voll ausgeglichen wird. Im Folgenden wird untersucht, ob dieses Urteil als Blaupause für eine anfechtungsfeste Restrukturierung einzelner Verbindlichkeiten dienen kann.
Mit der vorliegenden, parallel entsprechend in 10 weiteren Verfahren ergangenen Entscheidung behandelte der BGH zum wiederholten Male das Geschäftsmodell der Accessio Wertpapierhandelshaus AG („A AG“, früher: Wertpapierhandelshaus Driver & Bengsch AG). Die klagenden Anleger, zunächst nur akquiriert durch ein Tagesgeldkonto mit besonders attraktiven Zinsen, schlossen im Weiteren mit dieser einen Vermögensverwaltungsvertrag ab. Zur Abwicklung der Wertpapiergeschäfte eröffneten sie über die A AG zugleich ein Depotkonto bei der beklagten Discount-Brokerin. Für dieses erhielt die A AG eine Transaktionsvollmacht. Die Discount-Brokerin schuldete nach den Vertragsdokumenten über die gesetzlichen Aufklärungs- und Erkundigungspflichten bei Auftragsausführung hinaus keine Anlageberatung („execution-only-business“). Durch nach ihrer Behauptung fehlerhafte Anlageberatung der A AG erlitten die Anleger einen Schaden. In dem Rechtsstreit verlangten sie dessen Ersatz von der Discount-Brokerin, da die A AG zwischenzeitlich insolvent wurde.
Zum Zweck der Kapitalanlage beteiligte sich der Bekl. an einer Publikumsgesellschaft. Diese war als (mehrgliedrige) atypische stille Gesellschaft organisiert (vgl. a. BGHZ 199, 104 = DNotZ 2014, 374 = NZG 2013, 1422 = DStR 2014, 45 Rn. 18). Der Gesellschaftsvertrag („GV“) sah für diejenigen Gesellschafter, die wie der Bekl. ihre Einlage in Form einer Einmaleinlage erbracht hatten, eine jährliche gewinnunabhängige Ausschüttung vor. Es sollte sich dabei ausdrücklich nicht um eine Garantieverzinsung handeln. Ende 2009 wurde die stille Gesellschaft durch Mehrheitsbeschluss der Stillen aufgelöst. Nach dem GV waren die Stillen im Falle ihres Ausscheidens sowie bei „Liquidation des Unternehmens“ des Geschäftsinhabers verhältnismäßig an dem jeweils seit ihrem Beitritt gebildeten Vermögen einschließlich der stillen Reserven sowie eines evtl. Geschäftswerts zu beteiligen (Auseinandersetzungswert). Den sich hiernach für den Bekl. auf seinem Kapitalkonto ergebenden Negativsaldo sollte dieser durch Erstattung der von ihm erhaltenen gewinnunabhängigen Auszahlungen ausgleichen. Anders als das LG als Berufungsinstanz bejahte der BGH auf Grundlage des GV einen Rückerstattungsanspruch der klagenden Geschäftsinhaberin.
Analysis of the long-term effect of the MBST® nuclear magnetic resonance therapy on gonarthrosis
(2016)
Ground or aerial robots equipped with advanced sensing technologies, such as three-dimensional laser scanners and advanced mapping algorithms, are deemed useful as a supporting technology for first responders. A great deal of excellent research in the field exists, but practical applications at real disaster sites are scarce. Many projects concentrate on equipping robots with advanced capabilities, such as autonomous exploration or object manipulation. In spite of this, realistic application areas for such robots are limited to teleoperated reconnaissance or search. In this paper, we investigate how well state-of-the-art and off-the-shelf components and algorithms are suited for reconnaissance in current disaster-relief scenarios. The basic idea is to make use of some of the most common sensors and deploy some widely used algorithms in a disaster situation, and to evaluate how well the components work for these scenarios. We acquired the sensor data from two field experiments, one from a disaster-relief operation in a motorway tunnel, and one from a mapping experiment in a partly closed down motorway tunnel. Based on these data, which we make publicly available, we evaluate state-of-the-art and off-the-shelf mapping approaches. In our analysis, we integrate opinions and replies from first responders as well as from some algorithm developers on the usefulness of the data and the limitations of the deployed approaches, respectively. We discuss the lessons we learned during the two missions. These lessons are interesting for the community working in similar areas of urban search and rescue, particularly reconnaissance and search.
Purpose
To assess the feasibility of prostate ¹H MR spectroscopic imaging (MRSI) using low-power spectral-spatial (SPSP) pulses at 7T, exploiting accurate spectral selection and spatial selectivity simultaneously.
Methods
A double spin-echo sequence was equipped with SPSP refocusing pulses with a spectral selectivity of 1 ppm. Three-dimensional prostate ¹H-MRSI at 7T was performed with the SPSP-MRSI sequence using an 8-channel transmit array coil and an endorectal receive coil in three patients with prostate cancer and in one healthy subject. No additional water or lipid suppression pulses were used.
Results
Prostate ¹H-MRSI could be obtained well within specific absorption rate (SAR) limits in a clinically feasible time (10 min). Next to the common citrate signals, the prostate spectra exhibited high spermine signals concealing creatine and sometimes also choline. Residual lipid signals were observed at the edges of the prostate because of limitations in spectral and spatial selectivity.
Conclusion
It is possible to perform prostate ¹H-MRSI at 7T with a SPSP-MRSI sequence while using separate transmit and receive coils. This low-SAR MRSI concept provides the opportunity to increase spatial resolution of MRSI within reasonable scan times.
Mit der Verabschiedung der Europäischen Güterrechtsverordnung für Ehegatten und eingetragene Partner hat der Unionsgesetzgeber die Vereinheitlichung des Kollisionsrechts in Europa weiter vorangetrieben. Zentraler Baustein beider Rechtsakte ist die Parteiautonomie, die mit Blick auf Eheleute an bewährte Traditionen anknüpft, für Lebenspartner aber eine echte Neuerung bringt.
Zehn Jahre nach Erlass des „Grünbuchs zu den Kollisionsnormen im Güterrecht“ vom 17.7.2006 hat der Rat der Europäischen Union am 24.6.2016 die EU-Ehegüterrechts-(„EuGüVO“) sowie die EU-Partnerschaftsverordnung („EuPartVO“) erlassen. Damit wird das europäische Güterkollisionsrecht fü rca. 16 Millionen „internationaler Paare“ in der EU auf eine neue, einheitliche Grundlage gestellt. Anders als ursprünglich geplant, handelt es sich bei beiden Verordnungen nicht um gesamteuropäische Rechtsakte, da die für Art. 81 Abs. 3 AEUV erforderliche Einstimmigkeit unter den Mitgliedstaaten letztlich nicht erreicht werden konnte. Das Scheitern der ersten Verordnungsvorschläge aus dem Jahr 2011 war dabei dem Umstand geschuldet, dass rechtspolitisch von Anfang an eine Verknüpfung beider Regelungsmaterien gewollt war. Mit Blick auf die Einführung einheitlicher güterrechtlicher Regelungen für eingetragene Partnerschaften war aber nicht nur das „Ob“ und „Wie“ etwaiger Rechtswahlmöglichkeiten heftig umstritten. Insbesondere diejenigen Mitgliedstaaten, die dem Rechtsinstitut der eingetragenen Lebenspartnerschaft kritisch gegenüberstehen, sahen in der Einführung einheitlicher Kollisionsnormen die Gefahr einer zwangsweisen Durchsetzung dieses Rechtsinstituts „durch die Hintertür“. Vor diesem Hintergrund erwies sich – ebenso wie schon bei der Rom III-VO – das Verfahren zur verstärkten Zusammenarbeit(Art. 20 EUV i.V.m. Art. 326 ff. AEUV) als probates Mittel, um den Integrationsprozess im Bereich des europäischen Kollisionsrechts voranzutreiben. Achtzehn Mitgliedstaaten nehmen an dieser Verstärkten Zusammenarbeit teil.
In der EU richtet sich das auf unterhaltsrechtliche Sachverhalte mit grenzüberschreitendem Bezug anwendbare Recht seit dem 18. Juni 2011 nach dem Haager Protokoll über das auf Unterhaltspflichten anwendbare Recht vom 23. November 2007 („HUP“). Dieser Rechtsakt, der EU-weit anwendbar ist, hat das Haager Unterhaltsübereinkommen von 1973 („HUÜ“) ersetzt und das Unterhaltskollisionsrecht in der EU auf eine neue, einheitliche Grundlage gestellt. Bei den Vorschriften des HUP handelt es sich um sog. lois universelles, die unabhängig davon gelten, welche Staatsangehörigkeit die unterhaltsberechtigte bzw. die unterhaltsverpflichtete Person haben. Zu beachten ist aber, dass die Bundesrepublik Deutschland ebenso wie die Türkei, die Schweiz, Japan und Albanien das HUÜ ratifiziert hatten. Für die Nicht-EU-Staaten besteht aber keine Bindung an die Vorschriften des HUP, so dass sich im Verhältnis zu ihnen die Frage stellt, ob das HUÜ weiterhin Anwendung finden kann. Die Problematik ist gerade im Hinblick auf die erweiterten Rechtswahlmöglichkeiten des HUP von erheblicher praktischer Relevanz.
Die Entscheidung in der Rechtssache Bohez /Wiertz bot dem EuGH Gelegenheit, zur Abgrenzung der Anwendungsbereiche von Brüssel I-(jetzt: Brüssel Ia-) und Brüssel IIa-VO Stellung zu nehmen. Den Ausgangspunkt bildete dabei ein familienrechtlicher Sachverhalt, nämlich die zwangsweise Durchsetzung des Umgangsrechts eines Vaters im Hinblick auf seine beiden Kinder. Auf den ersten Blick lag daher eine Anwendung der auf Verfahren betreffend die elterliche Verantwortung bezogenen Brüssel IIa-VO nahe. Andererseits schien auch eine Argumentation denkbar, wonach es sich bei dem zu vollstreckenden Anspruch auf Zahlung des Zwangsgeldes um eine Geldforderung handele, deren Vollstreckung nach der Brüssel I-VO zu erfolgen habe.
Was vordergründig die Ermittlung des einschlägigen EU-Rechtsaktes betraf, erwies sich bei genauerer Betrachtung als Bestimmung der dogmatischen Rechtsnatur des Zwangsgeldes.
The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.
Hintergrund
Die Anwendung und das Verständnis von Statistik sind sehr wichtig für die biomedizinische Forschung und für die klinische Praxis. Dies gilt insbesondere auch zur Abschätzung der Möglichkeiten unterschiedlichster Diagnostik- und Therapieoptionen beim Glaukom. Die scheinbare Komplexität der Statistik, die zum Teil dem „gesunden Menschenverstand“ zu widersprechen scheint, zusammen mit der nur vorsichtigen Akzeptanz der Statistik bei vielen Medizinern können zu bewussten und unbewussten Manipulationen bei der Datendarstellung und -interpretation führen.
Ziel der Arbeit
Ziel ist die verständliche Darstellung einiger typischer Fehler in der medizinisch-statistischen Datenbehandlung.
Material und Methoden
Anhand hypothetischer Beispiele aus der Glaukomdiagnostik erfolgen die Darstellung der Wirkung eines hypotensiven Medikamentes sowie die Beurteilung der Ergebnisse eines diagnostischen Tests. Es werden die typischsten statistischen Einsatzbereiche und Irrtumsquellen ausführlich und verständlich analysiert
Ergebnisse
Mechanismen von Datenmanipulation und falscher Dateninterpretation werden aufgeklärt. Typische Irrtumsquellen bei der statistischen Auswertung und Datendarstellung werden dabei erläutert.
Schlussfolgerungen
Die erläuterten praktischen Beispiele zeigen die Notwendigkeit, die Grundlagen der Statistik zu verstehen und korrekt anwenden zu können. Fehlendes Grundlagenwissen und Halbwissen der medizinischen Statistik können zu folgenschweren Missverständnissen und falschen Entscheidungen in der medizinischen Forschung, aber auch in der klinischen Praxis führen.
An equitable graph coloring is a proper vertex coloring of a graph G where the sizes of the color classes differ by at most one. The equitable chromatic number is the smallest number k such that G admits such equitable k-coloring. We focus on enumerative algorithms for the computation of the equitable coloring number and propose a general scheme to derive pruning rules for them: We show how the extendability of a partial coloring into an equitable coloring can be modeled via network flows. Thus, we obtain pruning rules which can be checked via flow algorithms. Computational experiments show that the search tree of enumerative algorithms can be significantly reduced in size by these rules and, in most instances, such naive approach even yields a faster algorithm. Moreover, the stability, i.e., the number of solved instances within a given time limit, is greatly improved.
Since the execution of flow algorithms at each node of a search tree is time consuming, we derive arithmetic pruning rules (generalized Hall-conditions) from the network model. Adding these rules to an enumerative algorithm yields an even larger runtime improvement.
Robotergestütztes System für ein verbessertes neuromuskuläres Aufbautraining der Beinstrecker
(2016)
Neuromuskuläres Aufbautraining der Beinstrecker ist ein wichtiger Bestandteil in der Rehabilitation und Prävention von Muskel-Skelett-Erkrankungen. Effektives Training erfordert hohe Muskelkräfte, die gleichzeitig hohe Belastungen von bereits geschädigten Strukturen bedeuten. Um trainingsinduzierte Schädigungen zu vermeiden, müssen diese Kräfte kontrolliert werden. Mit heutigen Trainingsgeräten können diese Ziele allerdings nicht erreicht werden. Für ein sicheres und effektives Training sollen durch den Einsatz der Robotik, Sensorik, eines Regelkreises sowie Muskel-Skelett-Modellen Belastungen am Zielgewebe direkt berechnet und kontrolliert werden. Auf Basis zweier Vorstudien zu möglichen Stellgrößen wird der Aufbau eines robotischen Systems vorgestellt, das sowohl für Forschungszwecke als auch zur Entwicklung neuartiger Trainingsgeräte verwendet werden kann.
Background and Objective
Effective leg extension training at a leg press requires high forces, which need to be controlled to avoid training-induced damage. In order to avoid high external knee adduction moments, which are one reason for unphysiological loadings on knee joint structures, both training movements and the whole reaction force vector need to be observed. In this study, the applicability of lateral and medial changes in foot orientation and position as possible manipulated variables to control external knee adduction moments is investigated. As secondary parameters both the medio-lateral position of the center of pressure and the frontal-plane orientation of the reaction force vector are analyzed.
Methods
Knee adduction moments are estimated using a dynamic model of the musculoskeletal system together with the measured reaction force vector and the motion of the subject by solving the inverse kinematic and dynamic problem. Six different foot conditions with varying positions and orientations of the foot in a static leg press are evaluated and compared to a neutral foot position.
Results
Both lateral and medial wedges under the foot and medial and lateral shifts of the foot can influence external knee adduction moments in the presented study with six healthy subjects. Different effects are observed with the varying conditions: the pose of the leg is changed and the direction and center of pressure of the reaction force vector is influenced. Each effect results in a different direction or center of pressure of the reaction force vector.
Conclusions
The results allow the conclusion that foot position and orientation can be used as manipulated variables in a control loop to actively control knee adduction moments in leg extension training.
Purpose
The most commonly used mobility assessments for screening risk of falls among older adults are rating scales such as the Tinetti performance oriented mobility assessment (POMA). However, its correlation with falls is not always predictable and disadvantages of the scale include difficulty to assess many of the items on a 3-point scale and poor specificity. The purpose of this study was to describe the ability of the new Aachen Mobility and Balance Index (AMBI) to discriminate between subjects with a fall history and subjects without such events in comparison to the Tinetti POMA Scale.
Methods
For this prospective cohort study, 24 participants in the study group and 10 in the control group were selected from a population of patients in our hospital who had met the stringent inclusion criteria. Both groups completed the Tinetti POMA Scale (gait and balance component) and the AMBI (tandem stance, tandem walk, ten-meter-walk-test, sit-to-stand with five repetitions, 360° turns, timed-up-and-go-test and measurement of the dominant hand grip strength). A history of falls and hospitalization in the past year were evaluated retrospectively. The relationships among the mobility tests were examined with Bland–Altmananalysis. Receiver-operated characteristics curves, sensitivity and specificity were calculated.
Results
The study showed a strong negative correlation between the AMBI (17 points max., highest fall risk) and Tinetti POMA Scale (28 points max., lowest fall risk; r = −0.78, p < 0.001) with an excellent discrimination between community-dwelling older people and a younger control group. However, there were no differences in any of the mobility and balance measurements between participants with and without a fall history with equal characteristics in test comparison (AMBI vs. Tinetti POMA Scale: AUC 0.570 vs. 0.598; p = 0.762). The Tinetti POMA Scale (cut-off <20 points) showed a sensitivity of 0.45 and a specificity of 0.69, the AMBI a sensitivity of 0.64 and a specificity of 0.46 (cut-off >5 points).
Conclusion
The AMBI comprises mobility and balance tasks with increasing difficulty as well as a measurement of the dominant hand-grip strength. Its ability to identify fallers was comparable to the Tinetti POMA Scale. However, both measurement sets showed shortcomings in discrimination between fallers and non-fallers based on a self-reported retrospective falls-status.
Für das Auftreten extremer Wetterereignisse werden für Kernkraftwerke Eintrittshäufigkeiten für nicht mehr beherrschbare Zustände von unter 10⁻⁴/a gefordert. Dies gilt auch für die Einwirkung von Blitzeinschlägen. Die bisherige Nachweisführung zu Blitz- und Überspannungsschutz eines KKW in Deutschland ist deterministisch. In diesem Bericht werden das Vorgehen für einen entsprechenden Nachweis für leittechnische Einrichtungen der Sicherheitstechnik von KKW, der zur geforderten Zielgröße der Eintrittshäufigkeit führt. Die Ergebnisse werden zusammenfassend bewertet.
The enormous diversity of seed traits is an intriguing feature and critical for the overwhelming success of higher plants. In particular, seed mass is generally regarded to be key for seedling development but is mostly approximated by using scanning methods delivering only two-dimensional data, often termed seed size. However, three-dimensional traits, such as the volume or mass of single seeds, are very rarely determined in routine measurements. Here, we introduce a device named phenoSeeder, which enables the handling and phenotyping of individual seeds of very different sizes. The system consists of a pick-and-place robot and a modular setup of sensors that can be versatilely extended. Basic biometric traits detected for individual seeds are two-dimensional data from projections, three-dimensional data from volumetric measures, and mass, from which seed density is also calculated. Each seed is tracked by an identifier and, after phenotyping, can be planted, sorted, or individually stored for further evaluation or processing (e.g. in routine seed-to-plant tracking pipelines). By investigating seeds of Arabidopsis (Arabidopsis thaliana), rapeseed (Brassica napus), and barley (Hordeum vulgare), we observed that, even for apparently round-shaped seeds of rapeseed, correlations between the projected area and the mass of seeds were much weaker than between volume and mass. This indicates that simple projections may not deliver good proxies for seed mass. Although throughput is limited, we expect that automated seed phenotyping on a single-seed basis can contribute valuable information for applications in a wide range of wild or crop species, including seed classification, seed sorting, and assessment of seed quality.
The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the regrown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha⁻¹, whereas the highest dry matter of 70% to 80% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439 288 MJ ha⁻¹; the energy recovery of the four scenarios from highest to lowest followed this order: (i) ≫ (iii) ≫ (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500 °C, associated with a net calorific value of 16.5–17.2 MJ kg⁻¹. All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multipurpose energy applications.
The Monte Carlo code FLUKA is used to simulate the production of a number of positron emitting radionuclides, ¹⁸F, ¹³N, ⁹⁴Tc, ⁴⁴Sc, ⁶⁸Ga, ⁸⁶Y, ⁸⁹Zr, ⁵²Mn, ⁶¹Cu and ⁵⁵Co, on a small medical cyclotron with a proton beam energy of 13 MeV. Experimental data collected at the TR13 cyclotron at TRIUMF agree within a factor of 0.6 ± 0.4 with the directly simulated data, except for the production of ⁵⁵Co, where the simulation underestimates the experiment by a factor of 3.4 ± 0.4. The experimental data also agree within a factor of 0.8 ± 0.6 with the convolution of simulated proton fluence and cross sections from literature. Overall, this confirms the applicability of FLUKA to simulate radionuclide production at 13 MeV proton beam energy.
Zur Anwendung des Eurocode 3 Teil 1-2 für die Heißbemessung und Anregungen für dessen Novellierung
(2016)
Die Eurocodes werden bis zum Jahr 2020 im Europäischen Komitee für Normung (CEN), Technisches Komitee TC 250, überarbeitet. In Vorbereitung auf die Eurocode-Novellierung haben engagierte Ingenieure im Rahmen der Initiative PraxisRegeln Bau (PRB) die für die praktische Anwendung häufig genutzten Teile des Eurocode 3 untersucht. Mit dem Ziel, die Praxistauglichkeit des Eurocode 3 für die Heißbemessung zu verbessern, wurden die bestehende Norm EN 1993 Teil 1-2 insbesondere in Bezug auf die Anwenderfreundlichkeit analysiert und Vorschläge für die europäische Novellierung erarbeitet. Die Analysen zeigen, dass durch Umstrukturierungen und durch die Einführung von Tabellen die Verständlichkeit und Anwenderfreundlichkeit der Regeln für die Heißbemessung bedeutend erhöht werden können.
Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl₃–(CH₂CH (OCO(CH₂)ₘCH₃))ₙ–Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated.
All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain.
Elastomers are exceptional materials owing to their ability to undergo large deformations before failure. However, due to their very low stiffness, they are not always suitable for industrial applications. Addition of filler particles provides reinforcing effects and thus enhances the material properties that render them more versatile for applications like tyres etc. However, deformation behavior of filled polymers is accompanied by several nonlinear effects like Mullins and Payne effect. To this day, the physical and chemical changes resulting in such nonlinear effect remain an active area of research. In this work, we develop a heterogeneous (or multiphase) constitutive model at the mesoscale explicitly considering filler particle aggregates, elastomeric matrix and their mechanical interaction through an approximate interface layer. The developed constitutive model is used to demonstrate cluster breakage, also, as one of the possible sources for Mullins effect observed in non-crystallizing filled elastomers.
Bonding of polymer-based microfluidics to polymer substrates still poses a challenge for Lab-On-a-Chip applications. Especially, when sensing elements are incorporated, patterned deposition of adhesives with curing at ambient conditions is required. Here, we demonstrate a fabrication method for fully printed microfluidic systems with sensing elements using inkjet and stereolithographic 3D-printing.
Plate osteosynthesis of displaced proximal phalangeal neck fractures of the hand allows early mobilization due to a stable internal fixation. Nevertheless, joint stiffness—because of soft tissue irritation—represents a common complication leading to high complication rates. Del Pinal et al. recently reported promising clinical results for a new, minimally invasive fixation technique with a cannulated headless intramedullary compression screw. Hence, the aim of this study was to compare plate fixation of proximal phalangeal neck fractures to less two less invasive techniques: Crossed k-wire fixation and intramedullary screw fixation. We hypothesized that these fixation techniques provide inferior stability when compared to plate osteosynthesis.
Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique.
Treatment of posttraumatic osteoarthritis of the radial column of the elbow joint remains a challenging yet common issue.
While partial joint replacement leads to high revision rates, radial head excision has shown to severely increase joint instability. Shortening osteotomy of the radius could be an option to decrease the contact pressure of the radiohumeral joint and thereby pain levels without causing valgus instability. Hence, the aim of this biomechanical study was to evaluate the effects of radial shortening on axial load distribution and valgus stability of the elbow joint.
Background/Aims: Common systems for the quantification of cellular contraction rely on animal-based models, complex experimental setups or indirect approaches. The herein presented CellDrum technology for testing mechanical tension of cellular monolayers and thin tissue constructs has the potential to scale-up mechanical testing towards medium-throughput analyses. Using hiPS-Cardiac Myocytes (hiPS-CMs) it represents a new perspective of drug testing and brings us closer to personalized drug medication. Methods: In the present study, monolayers of self-beating hiPS-CMs were grown on ultra-thin circular silicone membranes and deflect under the weight of the culture medium. Rhythmic contractions of the hiPS-CMs induced variations of the membrane deflection. The recorded contraction-relaxation-cycles were analyzed with respect to their amplitudes, durations, time integrals and frequencies. Besides unstimulated force and tensile stress, we investigated the effects of agonists and antagonists acting on Ca²⁺ channels (S-Bay K8644/verapamil) and Na⁺ channels (veratridine/lidocaine). Results: The measured data and simulations for pharmacologically unstimulated contraction resembled findings in native human heart tissue, while the pharmacological dose-response curves were highly accurate and consistent with reference data. Conclusion: We conclude that the combination of the CellDrum with hiPS-CMs offers a fast, facile and precise system for pharmacological, toxicological studies and offers new preclinical basic research potential.
Autoradiography is a well-established method of nuclear imaging. When different radionuclides are present simultaneously, additional processing is needed to distinguish distributions of radionuclides. In this work, a method is presented where aluminium absorbers of different thickness are used to produce images with different cut-off energies. By subtracting images pixel-by-pixel one can generate images representing certain ranges of β-particle energies. The method is applied to the measurement of irradiated reactor graphite samples containing several radionuclides to determine the spatial distribution of these radionuclides within pre-defined energy windows. The process was repeated under fixed parameters after thermal treatment of the samples. The greyscale images of the distribution after treatment were subtracted from the corresponding pre-treatment images. Significant changes in the intensity and distribution of radionuclides could be observed in some samples. Due to the thermal treatment parameters the most significant differences were observed in the ³H and ¹⁴C inventory and distribution.
Combined with the use of renewable energy sources for its production, hydrogen represents a possible alternative gas turbine fuel for future low-emission power generation. Due to the difference in the physical properties of hydrogen compared to other fuels such as natural gas, well-established gas turbine combustion systems cannot be directly applied to dry low NOₓ (DLN) hydrogen combustion. The DLN micromix combustion of hydrogen has been under development for many years, since it has the promise to significantly reduce NOₓ emissions. This combustion principle for air-breathing engines is based on crossflow mixing of air and gaseous hydrogen. Air and hydrogen react in multiple miniaturized diffusion-type flames with an inherent safety against flashback and with low NOₓ emissions due to a very short residence time of the reactants in the flame region. The paper presents an advanced DLN micromix hydrogen application. The experimental and numerical study shows a combustor configuration with a significantly reduced number of enlarged fuel injectors with high-thermal power output at constant energy density. Larger fuel injectors reduce manufacturing costs, are more robust and less sensitive to fuel contamination and blockage in industrial environments. The experimental and numerical results confirm the successful application of high-energy injectors, while the DLN micromix characteristics of the design point, under part-load conditions, and under off-design operation are maintained. Atmospheric test rig data on NOₓ emissions, optical flame-structure, and combustor material temperatures are compared to numerical simulations and show good agreement. The impact of the applied scaling and design laws on the miniaturized micromix flamelets is particularly investigated numerically for the resulting flow field, the flame-structure, and NOₓ formation.
The Dry-Low-NOₓ (DLN) Micromix combustion technology has been developed as low emission combustion principle for industrial gas turbines fueled with hydrogen or syngas. The combustion process is based on the phenomenon of jet-in-crossflow-mixing. Fuel is injected perpendicular into the air-cross-flow and burned in a multitude of miniaturized, diffusion-like flames. The miniaturization of the flames leads to a significant reduction of NOₓ emissions due to the very short residence time of reactants in the flame.
In the Micromix research approach, CFD analyses are validated towards experimental results. The combination of numerical and experimental methods allows an efficient design and optimization of DLN Micromix combustors concerning combustion stability and low NOₓ emissions.
The paper presents a comparison of several numerical combustion models for hydrogen and hydrogen-rich syngas. They differ in the complexity of the underlying reaction mechanism and the associated computational effort.
For pure hydrogen combustion a one-step global reaction is applied using a hybrid Eddy-Break-up model that incorporates finite rate kinetics. The model is evaluated and compared to a detailed hydrogen combustion mechanism derived by Li et al. including 9 species and 19 reversible elementary reactions. Based on this mechanism, reduction of the computational effort is achieved by applying the Flamelet Generated Manifolds (FGM) method while the accuracy of the detailed reaction scheme is maintained.
For hydrogen-rich syngas combustion (H₂-CO) numerical analyses based on a skeletal H₂/CO reaction mechanism derived by Hawkes et al. and a detailed reaction mechanism provided by Ranzi et al. are performed.
The comparison between combustion models and the validation of numerical results is based on exhaust gas compositions available from experimental investigation on DLN Micromix combustors.
The conducted evaluation confirms that the applied detailed combustion mechanisms are able to predict the general physics of the DLN-Micromix combustion process accurately. The Flamelet Generated Manifolds method proved to be generally suitable to reduce the computational effort while maintaining the accuracy of detailed chemistry.
Especially for reaction mechanisms with a high number of species accuracy and computational effort can be balanced using the FGM model.
We present an electromechanically coupled computational model for the investigation of a thin cardiac tissue construct consisting of human-induced pluripotent stem cell-derived atrial, ventricular and sinoatrial cardiomyocytes. The mechanical and electrophysiological parts of the finite element model, as well as their coupling are explained in detail. The model is implemented in the open source finite element code Code_Aster and is employed for the simulation of a thin circular membrane deflected by a monolayer of autonomously beating, circular, thin cardiac tissue. Two cardio-active drugs, S-Bay K8644 and veratridine, are applied in experiments and simulations and are investigated with respect to their chronotropic effects on the tissue. These results demonstrate the potential of coupled micro- and macroscopic electromechanical models of cardiac tissue to be adapted to experimental results at the cellular level. Further model improvements are discussed taking into account experimentally measurable quantities that can easily be extracted from the obtained experimental results. The goal is to estimate the potential to adapt the presented model to sample specific cell cultures.
Im Jahr 2015 wurden in Deutschland über drei Millionen Benzinautos und lediglich 12.363 Elektroautos neu zugelassen. Das ursprünglich von der Bundesregierung vorgegebene Ziel, dass bis 2020 eine Million E-Autos auf deutschen Straßen fahren (und bis 2030 sechs Millionen), rückt damit in immer weitere Ferne. Um das Ziel dennoch zu erreichen, plant die Bundesregierung nun eine staatliche Prämie für den Kauf von Elektroautos: Umwelt-, Verkehrs- und Wirtschaftsministerium haben gemeinsam ein Konzept entworfen, dem zufolge private Käufer zukünftig einen Zuschuss von 5.000 Euro beim Erwerb eines Elektroautos bekommen sollen. 40 Prozent dieses Zuschusses soll von den Autoherstellern getragen werden. Das Programm, das weitere ausgabenwirksame öffentliche Maßnahmen vorsieht, würde Kosten in Milliardenhöhe verursachen. Die beabsichtigte Subventionierung wirft die Frage auf, ob diese wirtschaftlich sinnvoll sind.