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The Pharmacokinetics and Metabolism of Lumiracoxib in Chimeric Humanized and Murinized FRG Mice
(2017)
The pharmacokinetics and metabolism of diclofenac in chimeric humanized and murinized FRG mice
(2018)
The pharmacokinetics of diclofenac were investigated following single oral doses of 10 mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9 µg/mL (n = 3) at 0.25 h post-dose with an AUCinf of 3.67 µg h/mL and an effective half-life of 0.86 h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31 µg/mL at 0.25 h post-dose with an AUCinf of 4.94 ± 2.93 µg h/mL and a half-life of 0.52 ± 0.03 h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53 µg/mL were seen 0.25 h post-dose with a mean AUCinf of 2.10 ± 0.49 µg h/mL and a half-life of 0.51 ± 0.49 h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans.
Slot die coating is applied to deposit thin and homogenous films in roll-to-roll and sheet-to-sheet applications. The critical step in operation is to choose suitable process parameters within the process window. In this work, we investigate an upper limit for stripe coatings. This maximum film thickness is characterized by stripe merging which needs to be avoided in a stable process. It is shown that the upper limit reduces the process window for stripe coatings to a major extent. As a result, stripe coatings at large coating gaps and low viscosities are only possible for relatively thick films. Explaining the upper limit, a theory of balancing the side pressure in the gap region in the cross-web direction has been developed.
Mit modernen nicht invasiven bildgebenden Verfahren lassen sich anhand der Fundusfotografie bzw. der optischen Verfilmung Aspekte der funktionellen und strukturellen retinalen Gefäßveränderungen objektiv untersuchen. Der Zustand und das Verhalten retinaler Gefäße beeinflussen im prä-, post- und kapillaren Bereich den Blutfluss und strömungsbedingte Stoffwechselverhältnisse passiv und aktiv über den Gefäßdurchmesser. Retinale Gefäße gleichen von Aufbau und Funktion den zerebralen Gefäßen und spiegeln den Zustand der Mikrozirkulation wider. Mithilfe von aus den Gefäßweiten berechneten Biomarkern soll eine Aussage über die Prognose von systemischen vaskulär bedingten Erkrankungen getroffen werden. Die statische retinale Gefäßanalyse befasst sich mit der Untersuchung des Zustandes der prä- und postkapillaren Gefäßdurchmesser der retinalen Mikrozirkulation anhand einer optischen Fundusaufnahme. Bei der dynamischen retinalen Gefäßanalyse wird der Längsschnitt eines retinalen Gefäßes nicht invasiv funktionell und strukturell über einen Zeitraum vor, während und nach einer spezifischen vaskulären Stimulation untersucht. Die genaue Methodologie der Auswertung und die Bezeichnung der Parameter variieren bei unterschiedlichen Ansätzen. Mittels retinaler Gefäßanalyse wurden bislang mehrere klinische Querschnitts- und Interventionsstudien in der Augenheilkunde und anderen Fachgebieten, inkl. Kardiologie, Neurologie, Neurochirurgie, Nephrologie, Gynäkologie, Sportmedizin, Diabetologie, Hypertensiologie usw. durchgeführt. Mit der statischen retinalen Gefäßanalyse steht eine kostengünstige, reproduzierbare, nicht invasive Screeningtechnik zur Verfügung, um eine prognostische Aussage über die Gefäßgesundheit eines individuellen Patienten zu treffen. Die dynamische retinale Gefäßanalyse besitzt ein weiteres diagnostisches Anwendungsspektrum als die statische, da sie das Verhalten retinaler Gefäße zeitkontinuierlich untersucht. Die Evaluation vaskulärer Erkrankungen sowie zerebro- bzw. kardiovaskulärer Morbidität und Mortalität mittels mehrerer methodologischer Modalitäten retinaler Gefäßanalyse mit ihren jeweiligen quantitativen Biomarkern bietet eine zukunftsträchtige diagnostische Perspektive. Die interdisziplinäre klinische Anwendung dieser vaskulären Biomarker gewinnt zunehmend an Bedeutung, sowohl in der Augenheilkunde als auch in anderen Fachgebieten.
BACKGROUND: Muscle stretch reflexes are widely considered to beneficially influence joint stability and power generation in the lower limbs. While in the upper limbs and especially in the muscles surrounding the shoulder joint such evidence is lacking. OBJECTIVE: To quantify the electromyographical response in the muscles crossing the shoulder of specifically trained overhead athletes to an anterior perturbation force. METHODS: Twenty healthy male participants performed six sets of different external shoulder rotation stretches on an isokinetic dynamometer over a range of amplitudes and muscle pre-activation moment levels. All stretches were applied with a dynamometer acceleration of 10,000∘/s2 and a velocity of 150∘/s. Electromyographical response was measured via sEMG. RESULTS: Consistent reflexes were not observed in all experimental conditions. The reflex latencies revealed a significant muscle main effect (F (2,228) = 99.31, p< 0.001; η2= 0.466; f= 0.934) and a pre-activation main effect (F (1,228) = 142.21, p< 0.001; η2= 0.384; f= 1.418). The stretch reflex amplitude yielded a significant pre-activation main effect (F (1,222) = 470.373, p< 0.001; η2= 0.679; f= 1.454). CONCLUSION: Short latency muscle reflexes showed a tendency to an anterior to posterior muscle recruitment whereby the main internal rotator muscles of the shoulder revealed the most consistent results.
After a liver tumor intervention the medical doctor has to compare both pre and postoperative CT acquisitions to ensure that all carcinogenic cells are destroyed. A correct assessment of the intervention is of vital importance, since it will reduce the probability of tumor recurrence. Some methods have been proposed to support the medical doctors during the assessment process, however, all of them focus on secondary tumors. In this paper a tool is presented that enables the outcome validation for both primary and secondary tumors. Therefore, a multiphase registration (preoperative arterial and portal phases) followed by a registration between the pre and postoperative CT images is carried out. The first registration is in charge of the primary tumors that are only visible in the arterial phase. The secondary tumors will be incorporated in the second registration step. Finally, the part of the tumor that was not covered by the necrosis is quantified and visualized. The method has been tested in 9 patients, with an average registration error of 1.41 mm.
This Research Briefing, issued in July 2010, concluded that:
- Small and medium-sized enterprises (SMEs) in Europe have long called for a matching legal form valid across the EU (similar to that of the European company (SE) for large firms)
- The main benefits would be the availability of uniform Europe-wide company structures, significant cost reductions for businesses and further integration of the internal market
- Given the differing national views regarding the concrete features of the new legal form there is currently no sign of an agreement being reached at the European level in the short term; however, it is possible that progress will be made in negotiations during the year
- The key issues being discussed in depth are company formation, transnationality and employee participation rights in the new European private company (SPE).
Wenn durch innovative, automatisierte Güterwagen betriebswirtschaftliche Vorteile nutzbar gemacht werden sollen, muss die Migration auf das neue System in sinnvollen Teilschritten unter Berücksichtigung der organisationellen und betrieblichen Vereinbarkeit vorgenommen werden. Eine stufenweise Migration mit Nachrüstbarkeit und Kompatibilität kann die optimale Ausstattungsvariante für die unterschiedlichen Betriebsszenarien sowie eine Steigerung der Wirtschaftlichkeit des Gesamtsystems bieten.
For smaller railway operators or those with a diverse fleet, it can be difficult to collect sufficient data to improve maintenance programs. At the same time, new rules such as entity in charge of maintenance – ECM – regulations impose an additional workload by requiring a dedicated maintenance management system and specific reports. The RailCrowd platform sets out to facilitate compliance with ECM and similar regulations while at the same time pooling anonymised fleet data across operators to form virtual fleets, providing greater data insights.
Vor dem Hintergrund zunehmender gesellschaftlicher Veränderungen bei den Lebens- und Familienformen hat es sich die Commission on European Family Law (CEFL) seit 2001 zum Ziel gesetzt, unverbindliche Regelungsvorschläge für ein europaweit einheitliches Familienrecht zu schaffen. Die Vorstellung und Diskussion dieser auf rechtsvergleichender Basis erstellten Principles erfolgt auf den regelmäßig veranstalteten Tagungen der CEFL. Die nunmehr fünfte Konferenz zum Thema „Family Law and Culture in Europe – Developments, Challenges and Opportunities“ fand erstmals in Deutschland statt. Ausgerichtet wurde die Veranstaltung, zu der ca. 200 Teilnehmerinnen und Teilnehmern aus Wissenschaft und Praxis aus insgesamt 33 Ländern angereist waren, von Nina Dethloff (Direktorin des Instituts für Deutsches, Europäisches und Internationales Familienrecht an der Universität Bonn), Katharina Boele-Woelki (Direktorin des Utrecht Centre for European Research into Family Law und Preisträgerin des Anneliese Maier-Forschungspreises der Alexander von Humboldt-Stiftung) und Werner Gephart (Direktor des Käte Hamburger Kollegs „Recht als Kultur“).
Bereits 2015 wurde in der Zeitschrift „Qualität in der Wissenschaft“ (QiW) über das Kooperationsprojekt „Guter Studienstart im Ingenieurbereich“, das Orientierungssemester von RWTH und FH Aachen, berichtet. In diesem Artikel legen wir den Schwerpunkt auf die Entwicklung des Projekts in den Jahren 2015 bis 2018 und geben eine Rückschau sowie einen Ausblick auf die Entwicklungsperspektiven nach dem offiziellen Projektende.
Does stiffer electoral competition reduce political shirking? For a micro-analysis of this question, I construct a new data set spanning the years 2005 to 2012 covering biographical and political information about German Members of Parliament (MPs), including their attendance rates in voting sessions. For the parliament elected in 2009, I show that indeed opposition party MPs who expect to face a close race in their district show significantly and relevantly lower absence rates in parliament beforehand. MPs of governing parties seem not to react significantly to electoral competition. These results are confirmed by an analysis of the parliament elected in 2005, by several robustness checks, and also by employing an instrumental variable strategy exploiting convenient peculiarities of the German electoral system. The study also shows how MPs elected via party lists react to different levels of electoral competition.
Divided government is often thought of as causing legislative deadlock. I investigate the link between divided government and economic reforms using a novel data set on welfare reforms in US states between 1978 and 2010. Panel data regressions show that, under divided government, a US state is around 25% more likely to adopt a welfare reform than under unified government. Several robustness checks confirm this counter-intuitive finding. Case study evidence suggests an explanation based on policy competition between governor, senate, and house.
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.
Anmerkung zu EuGH, Urt. v. 1.3.2011, Rs. C-236/09 Association belge des Consomma-teurs Test-Achats
(2011)
Impact of electric propulsion technology and mission requirements on the performance of VTOL UAVs
(2018)
One of the engineering challenges in aviation is the design of transitioning vertical take-off and landing (VTOL) aircraft. Thrust-borne flight implies a higher mass fraction of the propulsion system, as well as much increased energy consumption in the take-off and landing phases. This mass increase is typically higher for aircraft with a separate lift propulsion system than for aircraft that use the cruise propulsion system to support a dedicated lift system. However, for a cost–benefit trade study, it is necessary to quantify the impact the VTOL requirement and propulsion configuration has on aircraft mass and size. For this reason, sizing studies are conducted. This paper explores the impact of considering a supplemental electric propulsion system for achieving hovering flight. Key variables in this study, apart from the lift system configuration, are the rotor disk loading and hover flight time, as well as the electrical systems technology level for both batteries and motors. Payload and endurance are typically used as the measures of merit for unmanned aircraft that carry electro-optical sensors, and therefore the analysis focuses on these particular parameters.
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.
A future bio-economy should not only be based on renewable raw materials but also in the raise of carbon yields of existing production routes. Microbial electrochemical technologies are gaining increased attention for this purpose. In this study, the electro-fermentative production of biobutanol with C. acetobutylicum without the use of exogenous mediators is investigated regarding the medium composition and the reactor design. It is shown that the use of an optimized synthetic culture medium allows higher product concentrations, increased biofilm formation, and higher conductivities compared to a synthetic medium supplemented with yeast extract. Moreover, the optimization of the reactor system results in a doubling of the maximum product concentrations for fermentation products. When a working electrode is polarized at −600 mV vs. Ag/AgCl, a shift from butyrate to acetone and butanol production is induced. This leads to an increased final solvent yield of Yᴀᴃᴇ = 0.202 gg⁻¹ (control 0.103 gg⁻¹), which is also reflected in a higher carbon efficiency of 37.6% compared to 23.3% (control) as well as a fourfold decrease in simplified E-factor to 0.43. The results are promising for further development of biobutanol production in bioelectrochemical systems in order to fulfil the principles of Green Chemistry.
Das verbraucherschützende Widerrufsrecht ist in die Jahre gekommen. Als Ergebnis der zunehmenden Rechtszersplitterung im europäischen Richtlinienrecht hat sich eine unüberschaubare Bandbreite an Ausgestaltungsformen in den mitgliedstaatlichen Rechtssystemen herausgebildet. Effektivitätseinbußen, Wettbewerbsverzerrungen und ein hohes Maß an Rechtsunsicherheit sind die Folgen. Zurückführen lässt sich die kostenintensive Fragmentierung des Verbrauchervertragsrechts auf die bisherige Regelungspolitik der Mindestharmonisierung, die es den Mitgliedstaaten erlaubt, von dem durch die Richtlinien gesetzten Mindeststandard durch „überschießende Umsetzung” abzuweichen. Der Unionsgesetzgeber versucht dem vermehrt durch einen Prozess der Vollharmonisierung zu begegnen: Neben Reformen der Richtlinie über Verbraucherkredite (VerbrKrRL) sowie der Timesharing-Richtlinie (TimesharingRL), liegt seit dem 8. Oktober 2008 nunmehr auch der Entwurf einer Rahmenrichtlinie über die Rechte der Verbraucher (VRRL-E) vor. Danach sollen die bisherigen Richtlinien über Haustürgeschäfte (HaustürgeschäfteRL), Fernabsatzverträge (FARL), missbräuchliche Klauseln sowie Verbrauchsgüterkäufe vereinigt werden. Für das verbraucherschützende Widerrufsrecht ist damit zum einen die Herausbildung einheitlicher Kernelemente verbunden, zum anderen tritt es in Konkurrenz zu umfassenden Informationspflichten, die ebenfalls den Schutz des Verbrauchers vor dem unüberlegten Abschluss riskanter bzw. nachteiliger Verträge zum Ziel haben.
Angesichts dieser Entwicklung stellt sich im Folgenden die Frage nach der Zukunft des unionsrechtlichen Widerrufsrechts. Von besonderer Bedeutung ist dabei die Klärung des Verhältnisses zu den verbraucherschützenden Informationspflichten. Dazu bedarf es zunächst der Herausarbeitung einheitlicher Kernelemente des Widerrufsrechts im vollharmonisierten Richtlinienrecht (II.) sowie einer Systematisierung der sekundärrechtlichen Informationspflichten im Anschluss eine kritische Gegenüberstellung der Vor- und Nachteile beider Schutzinstrumente erfolgen kann (IV.).
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.
Das Forschungsprojekt Produktionseffizienz in der Kleinserie (ProeK) erarbeitet kostengünstige und effiziente Lösungsansätze für Prozessketten im Zukunftsfeld der Elektromobilität. Das Teilprojekt Karosserie setzt diese Zielsetzung durch innovative und praxisorientierte Produkt- und Prozesskonzepte mit neuartigen bauteilintegrierten Vorrichtungsfunktionen (BiV) um. Im Teilprojekt Außenhaut sollen Toleranzen adaptiv durch Anpassungen der Prozessparameter sowie Bauteilmanipulation kompensiert werden.
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.
Geld-zurück-Garantien erlangen in der Unternehmenspraxis eine immer größere Bedeutung, vor allem weil sie als probates Mittel zur Signalisierung hochwertiger Qualität angesehen werden – eine Annahme, die bislang wissenschaftlich ungeprüft geblieben ist. Vor diesem Hintergrund wird im vorliegenden Beitrag eine umfassende empirische Untersuchung der kaufverhaltensrelevanten Wirkungen dieses Marketinginstrumentes vorgenommen. Die Ergebnisse verdeutlichen zum einen, dass eine Geld-zurück-Garantie nur unter bestimmten Bedingungen als Qualitätssignal wirkt. Dies hängt neben der Art des Produktes (Erfahrungs- vs. Suchgut) insbesondere von der Ausprägung des für die Qualitätsbeurteilung besonders diagnostischen Merkmals Marke sowie von der Produktkenntnis der Konsumenten ab. Zum anderen zeigt sich aber auch, dass eine Geld-zurück-Garantie affektive Konsumentenreaktionen auslöst, die die Kaufabsicht von Konsumenten zusätzlich erhöhen können. Zusammenfassend stellen wir fest, dass eine Geld-zurück-Garantie – entgegen bisheriger Erwartungen aus der Praxis – nicht zwingend ein Qualitätsindikator ist, stattdessen entfaltet sie aber bisher unbeachtete affektive Wirkungen, die insbesondere auf ihre absichernde Funktion von etwaigen Fehlentscheidungen beim Kauf zurückzuführen sind.
Das Ziel des Deutschen Corporate Governance Kodex (DCGK) besteht in der Verbesserung der Transparenz und Qualität der deutschen Corporate Governance, wobei die Sanktionierung der Nichteinhaltung des DCGK einzig durch etwaige Kapitalmarktreaktionen erfolgt. Folgende Befunde sprechen jedoch dafür, dass durch die Abgabe der Entsprechenserklärung gem. § 161 AktG die für das Enforcement des Kodex angenommene Selbstregulierung durch den Kapitalmarkt nicht stattfindet, und demnach Verbesserungsbedarf besteht
This paper investigates the extent to which corporate governance affects the cost of debt and equity capital of German exchange-listed companies. I examine corporate governance along three dimensions: financial information quality, ownership structure and board structure. The results suggest that firms with high levels of financial transparency and bonus compensations face lower cost of equity. In addition, block ownership is negatively related to firms' cost of equity when the blockholders are other firms, managers or founding-family members. Consistent with the conjecture that agency costs increase with firm size, I find significant cost of debt effects only in the largest German companies. Here, the creditors demand lower cost of debt from firms with block ownerships held by corporations or banks. My findings demonstrate that a uniform set of governance attributes is unlikely to satisfy suppliers of debt and equity capital equally.
BACKGROUND
Immunosuppression is often considered as an indication for antibiotic prophylaxis to prevent surgical site infections (SSI) while performing skin surgery. However, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited.
PATIENTS AND METHODS
All patients of the Department of Dermatology and Allergology at the University Hospital of RWTH Aachen in Aachen, Germany, who underwent hospitalization for a dermatologic surgery between June 2016 and January 2017 (6 months), were followed up after surgery until completion of the wound healing process. The follow-up addressed the occurrence of SSI and the need for systemic antibiotics after the operative procedure. Immunocompromised patients were compared with immunocompetent patients. The investigation was conducted as a retrospective analysis of patient records.
RESULTS
The authors performed 284 dermatologic surgeries in 177 patients. Nineteen percent (54/284) of the skin surgery was performed on immunocompromised patients. The most common indications for surgical treatment were nonmelanoma skin cancer and malignant melanomas. Surgical site infections occurred in 6.7% (19/284) of the cases. In 95% (18/19), systemic antibiotic treatment was needed. Twenty-one percent of all SSI (4/19) were seen in immunosuppressed patients.
CONCLUSION
According to the authors' data, immunosuppression does not represent a significant risk factor for SSI after dermatologic surgery. However, larger prospective studies are needed to make specific recommendations on the use of antibiotic prophylaxis while performing skin surgery in these patients.
The available data on complications after dermatologic surgery have improved over the past years. Particularly, additional risk factors have been identified for surgical site infections (SSI). Purulent surgical sites, older age, involvement of head, neck, and acral regions, and also the involvement of less experienced surgeons have been reported to increase the risk of the SSI after dermatologic surgeries.1 In general, the incidence of SSI after skin surgery is considered to be low.1,2 However, antibiotics in dermatologic surgeries, especially in the perioperative setting, seem to be overused,3,4 particularly regarding developing antibiotic resistances and side effects.
Immunosuppression has been recommended to be taken into consideration as an additional indication for antibiotic prophylaxis to prevent SSI after skin surgery in special cases.5,6 However, these recommendations do not specify the exact dermatologic surgeries, and were not specifically developed for dermatologic surgery patients and treatments, but adopted from other surgical fields.6 According to the survey conducted on American College of Mohs Surgery members in 2012, 13% to 29% of the surgeons administered antibiotic prophylaxis to immunocompromised patients to prevent SSI while performing dermatologic surgery on noninfected skin,3 although this was not recommended by Journal of the American Academy of Dermatology Advisory Statement. Indeed, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited. However, it is possible that due to the insufficient evidence on the risk of SSI occurrence in this patient group, dermatologic surgeons tend to overuse perioperative antibiotic prophylaxis.
To make specific recommendations on the use of antibiotic prophylaxis in immunosuppressed patients in the field of skin surgery, more information about the incidence of SSI after dermatologic surgery in these patients is needed. The aim of this study was to fill this data gap by investigating whether there is an increased risk of SSI after skin surgery in immunocompromised patients compared with immunocompetent patients.
For fuel flexibility enhancement hydrogen represents a possible alternative gas turbine fuel within future low emission power generation, in case of hydrogen production by the use of renewable energy sources such as wind energy or biomass. Kawasaki Heavy Industries, Ltd. (KHI) has research and development projects for future hydrogen society; production of hydrogen gas, refinement and liquefaction for transportation and storage, and utilization with gas turbine / gas engine for the generation of electricity. In the development of hydrogen gas turbines, a key technology is the stable and low NOx hydrogen combustion, especially Dry Low Emission (DLE) or Dry Low NOx (DLN) hydrogen combustion. Due to the large 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 for DLE hydrogen combustion. Thus, the development of DLE hydrogen combustion technologies is an essential and challenging task for the future of hydrogen fueled gas turbines. The DLE Micro-Mix combustion principle for hydrogen fuel has been in development for many years to significantly reduce NOx emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized “diffusion-type” flames. The major advantages of this combustion principle are the inherent safety against flashback and the low NOx-emissions due to a very short residence time of the reactants in the flame region of the micro-flames.
On the flight performance impact of landing gear drag reduction methods for unmanned air vehicles
(2018)
The flight performance impact of three different landing gear configurations on a small, fixed-wing UAV is analyzed with a combination of RANS CFD calculations and an incremental flight performance algorithm. A standard fixed landing gear configuration is taken as a baseline, while the influence of retracting the landing gear or applying streamlined fairings is investigated. A retraction leads to a significant parasite drag reduction, while also fairings promise large savings. The increase in lift-to-drag ratio is reduced at high lift coefficients due to the influence of induced drag. All configurations are tested on three different design missions with an incremental flight performance algorithm. A trade-off study is performed using the retracted or faired landing gear's weight increase as a variable. The analysis reveals only small mission performance gains as the aerodynamic improvements are negated by weight penalties. A new workflow for decision-making is presented that allows to estimate if a change in landing gear configuration is beneficial for a small UAV.
Postural and metabolic benefits of using a forearm support walker in older adults with impairments
(2019)
Im Mai 2012 fand in Hamburg erstmals das „Junge Forum Hochschul- und Mediendidaktik“ statt, im Juni 2013 folgte in Potsdam die zweite Auflage als „Junges Forum Medien und Hochschulentwicklung“. 2014 wurde das dritte „Forum“ in Dresden und 2015 das vierte in Düsseldorf ausgerichtet. Das fünfte Forum wird 2016 an der Technischen Universität Darmstadt stattfinden. Initiiert und organisiert wird die Veranstaltung stets von jungen Praktikerinnen und Praktikern sowie Forscherinnen und Forschern mit dem Ziel, dem ‚Nachwuchs‘ in diesem Bereich ein Austauschforum zu geben. Der vorliegende Artikel stellt die konzeptionellen Überlegungen vor, die hinter diesen Treffen stehen. Er zeigt im Rückgriff auf Netzwerktheorie und aktuelle Diskussionen um Professionalisierung und Third Space, wieso für dieses Format ein aktueller Bedarf besteht, und begründet dann im Rückgriff auf didaktische Konzepte auch die methodische Gestaltung der Veranstaltungen. Unsere These: Das kooperative Lernen in Netzwerken ist ein wichtiger Baustein für die Professionalisierung des hochschul- und mediendidaktischen Nachwuchses.
Background
Impairment of neurovascular coupling (NVC) was recently reported in the context of subarachnoid hemorrhage and may correlate with disease severity and outcome. However, previous techniques to evaluate NVC required invasive procedures. Retinal vessels may represent an alternative option for non-invasive assessment of NVC.
Methods
A prototype of an adapted retinal vessel analyzer was used to assess retinal vessel diameter in mice. Dynamic vessel analysis (DVA) included an application of monochromatic flicker light impulses in predefined frequencies for evaluating NVC. All retinae were harvested after DVA and electroretinograms were performed.
Results
A total of 104 retinal scans were conducted in 21 male mice (90 scans). Quantitative arterial recordings were feasible only in a minority of animals, showing an emphasized reaction to flicker light impulses (8 mice; 14 scans). A characteristic venous response to flicker light, however, could observed in the majority of animals. Repeated measurements resulted in a significant decrease of baseline venous diameter (7 mice; 7 scans, p < 0.05). Ex-vivo electroretinograms, performed after in-vivo DVA, demonstrated a significant reduction of transretinal signaling in animals with repeated DVA (n = 6, p < 0.001).
Conclusions
To the best of our knowledge, this is the first non-invasive study assessing murine retinal vessel response to flicker light with characteristic changes in NVC. The imaging system can be used for basic research and enables the investigation of retinal vessel dimension and function in control mice and genetically modified animals.
Algal polysaccharides (extracellular polysaccharides) and carbon nanotubes (CNTs) were adsorbed on dioctadecyldimethylammonium bromide Langmuir monolayers to serve as a matrix for the incorporation of urease. The physicochemical properties of the supramolecular system as a monolayer at the air–water interface were investigated by surface pressure–area isotherms, surface potential–area isotherms, interfacial shear rheology, vibrational spectroscopy, and Brewster angle microscopy. The floating monolayers were transferred to hydrophilic solid supports, quartz, mica, or capacitive electrolyte–insulator–semiconductor (EIS) devices, through the Langmuir–Blodgett (LB) technique, forming mixed films, which were investigated by quartz crystal microbalance, fluorescence spectroscopy, and field emission gun scanning electron microscopy. The enzyme activity was studied with UV–vis spectroscopy, and the feasibility of the thin film as a urea sensor was essayed in an EIS sensor device. The presence of CNT in the enzyme–lipid LB film not only tuned the catalytic activity of urease but also helped to conserve its enzyme activity. Viability as a urease sensor was demonstrated with capacitance–voltage and constant capacitance measurements, exhibiting regular and distinctive output signals over all concentrations used in this work. These results are related to the synergism between the compounds on the active layer, leading to a surface morphology that allowed fast analyte diffusion owing to an adequate molecular accommodation, which also preserved the urease activity. This work demonstrates the feasibility of employing LB films composed of lipids, CNT, algal polysaccharides, and enzymes as EIS devices for biosensing applications.
Monitoring of organic acids (OA) and volatile fatty acids (VFA) is crucial for the control of anaerobic digestion. In case of unstable process conditions, an accumulation of these intermediates occurs. In the present work, two different enzyme-based biosensor arrays are combined and presented for facile electrochemical determination of several process-relevant analytes. Each biosensor utilizes a platinum sensor chip (14 × 14 mm²) with five individual working electrodes. The OA biosensor enables simultaneous measurement of ethanol, formate, d- and l-lactate, based on a bi-enzymatic detection principle. The second VFA biosensor provides an amperometric platform for quantification of acetate and propionate, mediated by oxidation of hydrogen peroxide. The cross-sensitivity of both biosensors toward potential interferents, typically present in fermentation samples, was investigated. The potential for practical application in complex media was successfully demonstrated in spiked sludge samples collected from three different biogas plants. Thereby, the results obtained by both of the biosensors were in good agreement to the applied reference measurements by photometry and gas chromatography, respectively. The proposed hybrid biosensor system was also used for long-term monitoring of a lab-scale biogas reactor (0.01 m³) for a period of 2 months. In combination with typically monitored parameters, such as gas quality, pH and FOS/TAC (volatile organic acids/total anorganic carbonate), the amperometric measurements of OA and VFA concentration could enhance the understanding of ongoing fermentation processes.
Background
Culture media containing complex compounds like yeast extract or peptone show numerous disadvantages. The chemical composition of the complex compounds is prone to significant variations from batch to batch and quality control is difficult. Therefore, the use of chemically defined media receives more and more attention in commercial fermentations. This concept results in better reproducibility, it simplifies downstream processing of secreted products and enable rapid scale-up. Culturing bacteria with unknown auxotrophies in chemically defined media is challenging and often not possible without an extensive trial-and-error approach. In this study, a respiration activity monitoring system for shake flasks and its recent version for microtiter plates were used to clarify unknown auxotrophic deficiencies in the model organism Bacillus pumilus DSM 18097.
Results
Bacillus pumilus DSM 18097 was unable to grow in a mineral medium without the addition of complex compounds. Therefore, a rich chemically defined minimal medium was tested containing basically all vitamins, amino acids and nucleobases, which are essential ingredients of complex components. The strain was successfully cultivated in this medium. By monitoring of the respiration activity, nutrients were supplemented to and omitted from the rich chemically defined medium in a rational way, thus enabling a systematic and fast determination of the auxotrophic deficiencies. Experiments have shown that the investigated strain requires amino acids, especially cysteine or histidine and the vitamin biotin for growth.
Conclusions
The introduced method allows an efficient and rapid identification of unknown auxotrophic deficiencies and can be used to develop a simple chemically defined tailor-made medium. B. pumilus DSM 18097 was chosen as a model organism to demonstrate the method. However, the method is generally suitable for a wide range of microorganisms. By combining a systematic combinatorial approach based on monitoring the respiration activity with cultivation in microtiter plates, high throughput experiments with high information content can be conducted. This approach facilitates media development, strain characterization and cultivation of fastidious microorganisms in chemically defined minimal media while simultaneously reducing the experimental effort.
False spectra formation in the differential two-channel scheme of the laser Doppler flowmeter
(2018)
Noise in the differential two-channel scheme of a classic laser Doppler flowmetry (LDF) instrument was studied. Formation of false spectral components in the output signal due to beating of electrical signals in the differential amplifier was found out. The improved block-diagram of the flowmeter was developed allowing to reduce the noise.
Synthetic mimics of natural high-performance structural materials have shown great and partly unforeseen opportunities for the design of multifunctional materials. For nacre-mimetic nanocomposites, it has remained extraordinarily challenging to make ductile materials with high stretchability at high fractions of reinforcements, which is however of crucial importance for flexible barrier materials. Here, highly ductile and tough nacre-mimetic nanocomposites are presented, by implementing weak, but many hydrogen bonds in a ternary nacre-mimetic system consisting of two polymers (poly(vinyl amine) and poly(vinyl alcohol)) and natural nanoclay (montmorillonite) to provide efficient energy dissipation and slippage at high nanoclay content (50 wt%). Tailored interactions enable exceptional combinations of ductility (close to 50% strain) and toughness (up to 27.5 MJ m⁻³). Extensive stress whitening, a clear sign of high internal dynamics at high internal cohesion, can be observed during mechanical deformation, and the materials can be folded like paper into origami planes without fracture. Overall, the new levels of ductility and toughness are unprecedented in highly reinforced bioinspired nanocomposites and are of critical importance to future applications, e.g., as barrier materials needed for encapsulation and as a printing substrate for flexible organic electronics.
As with most high-velocity free-surface flows, stepped spillway flows become self-aerated when the drop height exceeds a critical value. Due to the step-induced macro-roughness, the flow field becomes more turbulent than on a similar smooth-invert chute. For this reason, cascades are oftentimes used as re-aeration structures in wastewater treatment. However, for stepped spillways as flood release structures downstream of deoxygenated reservoirs, gas transfer is also of crucial significance to meet ecological requirements. Prediction of mass transfer velocities becomes challenging, as the flow regime differs from typical previously studied flow conditions. In this paper, detailed air-water flow measurements are conducted on stepped spillway models with different geometry, with the aim to estimate the specific air-water interface. Re-aeration performances are determined by applying the absorption method. In contrast to earlier studies, the aerated water body is considered a continuous mixture up to a level where 75% air concentration is reached. Above this level, a homogenous surface wave field is considered, which is found to significantly affect the total air-water interface available for mass transfer. Geometrical characteristics of these surface waves are obtained from high-speed camera investigations. The results show that both the mean air concentration and the mean flow velocity have influence on the mass transfer. Finally, an empirical relationship for the mass transfer on stepped spillway models is proposed.
The chemical imaging sensor is a semiconductor-based chemical sensor capable of visualizing pH and ion distributions. The spatial resolution depends on the lateral diffusion of photocarriers generated by illumination of the semiconductor substrate. In this study, two types of optical setups, one based on a bundle of optical fibers and the other based on a binocular tube head, were developed to project a hybrid illumination of a modulated light beam and a ring-shaped constant illumination onto the sensor plate. An improved spatial resolution was realized by the ring-shaped constant illumination, which suppressed lateral diffusion of photocarriers by enhanced recombination due to the increased carrier concentration.
Gleichstellungsabrede – Gestaltungsmöglichkeiten und -notwendigkeiten für die betriebliche Praxis
(2007)
Die SPAC-SE ist börsenfähig und damit eine für eine SPAC grundsätzlich geeignete Rechtsform. Die Tatsache, dass es sich hierbei (zunächst) um eine leere, arbeitnehmerlose Hülle handelt, ändert hieran nichts. Die Gründung einer solchen Vorrats-SE ist trotz fehlender Arbeitnehmerbeteiligung unter teleologischer Reduktion von Art. 12 II SE-VO zulässig. Im Gegenzug muss die Arbeitnehmerbeteiligung gemaß § 18 III SEBG analog nachgeholt werden, wenn das später erworbene Zielunternehmen auf die SPAC-SE verschmolzen werden soll. Aus gesellschaftsrechtlicher Sicht ist zu beachten, dass die SPAC-SE mit Sitz in Deutschland, welche auch den deutschen, aktienrechtlichen Bestimmungen unterliegt, nur bedingt für eine SPAC geeignet erscheint. Das deutsche Aktienrecht enthält strenge Regelungen, die der für eine SPAC-SE erforderlichen Flexibilität entgegenstehen können. Dies gilt insbesondere für das Erfordernis der Zustimmung der Hauptversammlung zur Akquisition des Zielunternehmens, die Rückzahlung des Treuhandvermögens an Aktionäre, die der Akquisition nicht zugestimmt haben und die Liquidation der SPAC-SE im Falle des Scheiterns des Erwerbs des Zielobjektes.