Entwicklung eines Multifunktionsinstruments für die laparoskopische Chirurgie

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Chirurgische Eingriffe werden zunehmend minimul-invasiv durchgeführt, um die Belastung der Patienten durch die Operation zu verringern. Die Innovation der hier vorgestellten technischen Lösung besteht darin,dass die einzelnen Instrumente, die für verschiedene Operationsschritte erforderlich sind, in einem gemeinsamen Handgriff zusammengefasst und damit im Operationsfeld simultan und rasch austauschbar vorgehalten werden können. Durch die Verwendung von verschiedenen Aktuatoren erfolgt der Wechsel zwischen den integrierten Insimmenten automatisiert, so dass eine Einhandbedienung gewährleistet ist

Radio Continuum Emission from the Magnetar SGR J1745-2900: Interaction with Gas Orbiting Sgr A*

We present radio continuum light curves of the magnetar SGR J1745$-$2900 and Sgr A* obtained with multi-frequency, multi-epoch Very Large Array observations between 2012 and 2014. During this period, a powerful X-ray outburst from SGR J1745$-$2900 occurred on 2013-04-24. Enhanced radio emission is delayed with respect to the X-ray peak by about seven months. In addition, the flux density of the emission from the magnetar fluctuates by a factor of 2 to 4 at frequencies between 21 and 41 GHz and its spectral index varies erratically. Here we argue that the excess fluctuating emission from the magnetar arises from the interaction of a shock generated from the X-ray outburst with the orbiting ionized gas at the Galactic center. In this picture, variable synchrotron emission is produced by ram pressure variations due to inhomogeneities in the dense ionized medium of the Sgr A West bar. The pulsar with its high transverse velocity is moving through a highly blue-shifted ionized medium. This implies that the magnetar is at a projected distance of $\sim0.1$ pc from Sgr A* and that the orbiting ionized gas is partially or largely responsible for a large rotation measure detected toward the magnetar. Despite the variability of Sgr A* expected to be induced by the passage of the G2 cloud, monitoring data shows a constant flux density and spectral index during this periodComment: 12 pages, 3 figures, ApJL (in press

A novel method for patient-oriented assignment of wheelchair cushions based on standardized laboratory testing procedures

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Rollstuhlsitzkissen sind die Schnittstelle zwischen Rollstuhl und Rollstuhlfahrer und übernehmen dabei Last übertragende und stabilisierende Aufgaben. Zusätzlich sollen sie helfen, Druckgeschwüre durch mechanische Entlastung und einen Abtransport von Feuchtigkeit und Wärme zu vermeiden. Die Auswahl eines Sitzkissen erfolgt dabei häufig anhand einer subjektiven Einschätzung der Sitzkisseneigenschaften, was die durchschnittliche Qualität der Versorgung negativ beeinflussen kann und unter Kostengesichtspunkten die Auswahl hochwirksamer Kissen nur schwer rechtfertigt. Dieser Artikel beschreibt ein Verfahren, Sitzkissen anhand von messtechnisch erfassten Kennwerten und einer standardisierten Patientenprofilerhebung auszuwählen. Dazu wird eine Übersicht über die am Markt erhältlichen Sitzkissen gegeben und Möglichkeiten erörtert, die Sitzkissen anhand von strukturierten Entscheidungshilfen nachvollziehbar auszuwählen und die Anforderungen des Patienten unterstützend einzuteilen und zuzuordnen.A wheelchair seat cushion represents the interface between the wheelchair and the wheelchair driver and has to manage the force transmission and the stabilization between both of them. An additional very important requirement is the prevention of pressure ulcers by pressure relief and the transfer of humidity and heat away from the patient. The allocation of a cushion to the patient happens normally on the base of a subjective description of the cushion without any transparent decision rules. Consequently the quality of this procedure could be improved by a better description of the cushion, based on standardized laboratory tests and by the development of decision tools helping to identify the main efforts of the user. This article describes a procedure that allows the allocation of wheelchair seat cushions based on the characteristic of cushions from standardized laboratory tests and on the brief description of the user. Additionally the existing principles for wheelchair cushions are listed, described and compared. The possibilities to develop structured decision tools for wheelchair cushions are discussed

Magneto-optical properties of Au upon the injection of hot spin-polarized electrons across Fe/Au(001) interfaces

We demonstrate a novel method for the excitation of sizable magneto-optical effects in Au by means of the laser-induced injection of hot spin-polarized electrons in Au/Fe/MgO(001) heterostructures. It is based on the energy- and spin-dependent electron transmittance of Fe/Au interface which acts as a spin filter for non-thermalized electrons optically excited in Fe. We show that after crossing the interface, majority electrons propagate through the Au layer with the velocity on the order of 1 nm/fs (close to the Fermi velocity) and the decay length on the order of 100 nm. Featuring ultrafast functionality and requiring no strong external magnetic fields, spin injection results in a distinct magneto-optical response of Au. We develop a formalism based on the phase of the transient complex MOKE response and demonstrate its robustness in a plethora of experimental and theoretical MOKE studies on Au, including our ab initio calculations. Our work introduces a flexible tool to manipulate magneto-optical properties of metals on the femtosecond timescale that holds high potential for active magneto-photonics, plasmonics, and spintronics

Late Quaternary evolution of gravel deposits in Tromper Wiek, South-western Baltic Sea

The Late Quaternary history of the Baltic Sea is marked by a complex sequence of glacial, lacustrine and marine phases (late Pleistocene, Baltic Ice Lake, Yoldia Lake, Ancylus Lake, Littorina Sea). Boomer data, acquired in October 2004, permitted to improve the knowledge of the late Quaternary geological evolution of Tromper Wiek, a semienclosed bay, located in the north-eastern part of Rügen Island. The sedimentary deposits can be subdivided in 6 seismic units (U1 to U6). The upper part of the lowest unit (U1) corresponds to Pleistocene till. Channels incise the top of this till (surface S2), probably created during the first drainage of the Baltic Sea during the Late Glacial. Subsequent channel filling (U2) occurred in two phases beginning with chaotic deposits, probably fluviatile of origin, followed by graded deposits. This filling was stopped by an erosive period with the formation of surface S3, showing channels at the same location as S2. The facies of the channel filling (U3 and U4), during a second phase, is similar to the first one, but resembles a prograding sediment body, intercalated between the two units in the shallower part. U3 shows a bar-shaped deposit at its top. The facies of U4 is very similar to a barrier/back-barrier facies similar to the facies of unit U5, partly composed of gravel. The deposits of U6 correspond to the post-Littorina Sea deposits. The presence of gravel is linked to coastal cliffs, in which chalk layers, pushed up by glaciers, alternate with sections of till and meltwater deposits and with submarine outcrops of till. Gravel deposits are present in unit U5. They are strongly linked to the presence of a barrier. Four of the six units show a barrier facies (U2, U3, U4 and U5); gravel deposits could be present inside all of these units and would represent a larger deposit than estimated previously

Evaluierung der Messmethoden zur Bewertung des therapeutischen Nutzens von Antidekubitus-Systemen

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Interface pressure measurement is today a most used technique for laboratory evaluation of support surfaces in prevention of pressure sores. This article describes the results of an experimental comparative evaluation of four modern pressure mapping Systems (Tekscan, Xsensor, Novel and FSA) using a special loading device.The tests generated dato on numerical accuracy, linearity and hysteresis. The results show that the accuracy of pressure mapping Systems is still limited and results obtained from different Systems can not be directly compared

Impact of Janus Kinase Inhibition with Tofacitinib on Fundamental Processes of Bone Healing

Both inflammatory diseases like rheumatoid arthritis (RA) and anti-inflammatory treatment of RA with glucocorticoids (GCs) or non-steroidal anti-inflammatory drugs (NSAIDs) negatively influence bone metabolism and fracture healing. Janus kinase (JAK) inhibition with tofacitinib has been demonstrated to act as a potent anti-inflammatory therapeutic agent in the treatment of RA, but its impact on the fundamental processes of bone regeneration is currently controversially discussed and at least in part elusive. Therefore, in this study, we aimed to examine the effects of tofacitinib on processes of bone healing focusing on recruitment of human mesenchymal stromal cells (hMSCs) into the inflammatory microenvironment of the fracture gap, chondrogenesis, osteogenesis and osteoclastogenesis. We performed our analyses under conditions of reduced oxygen availability in order to mimic the in vivo situation of the fracture gap most optimal. We demonstrate that tofacitinib dose-dependently promotes the recruitment of hMSCs under hypoxia but inhibits recruitment of hMSCs under normoxia. With regard to the chondrogenic differentiation of hMSCs, we demonstrate that tofacitinib does not inhibit survival at therapeutically relevant doses of 10-100 nM. Moreover, tofacitinib dose-dependently enhances osteogenic differentiation of hMSCs and reduces osteoclast differentiation and activity. We conclude from our data that tofacitinib may influence bone healing by promotion of hMSC recruitment into the hypoxic microenvironment of the fracture gap but does not interfere with the cartilaginous phase of the soft callus phase of fracture healing process. We assume that tofacitinib may promote bone formation and reduce bone resorption, which could in part explain the positive impact of tofacitinib on bone erosions in RA. Thus, we hypothesize that it will be unnecessary to stop this medication in case of fracture and suggest that positive effects on osteoporosis are likely