Correcting heading errors in optically pumped magnetometers through microwave interrogation

We demonstrate how to measure in-situ for heading errors of optically pumped magnetometers in geomagnetic fields. For this, we implement microwave-driven Rabi oscillations and Ramsey interferometry on hyperfine transitions as two independent methods to detect scalar systematics of free induction decay (FID) signals. We showcase the wide applicability of this technique by operating in the challenging parameter regime of compact vapor cells with imperfect pumping and high buffer gas pressure. In this system, we achieve suppression of large inaccuracies arising from nonlinear Zeeman (NLZ) shifts by up to a factor of 10 to levels below 0.6 nT. In the Ramsey method we accomplish this, even in arbitrary magnetic field directions, by employing a hyper-Ramsey protocol and optical pumping with adiabatic power ramps. For the Rabi technique, this level of accuracy is reached, despite associated drive-dependent shifts, by referencing Rabi frequency measurements to a complete atom-microwave coupling model that incorporates the microwave polarization structure.Comment: 6 pages, 4 figures + supplementary 16 pages, 10 figure

Standardized and quality-assured video-recorded examination in undergraduate education: informed consent prior to surgery

AbstractBackgroundCommunication skills combined with specialized knowledge are fundamental to the doctor–patient relationship in surgery. During a single-station video-recorded objective structured clinical examination (VOSCE), students were tasked with obtaining informed consent. Our aim was to develop a standardized and quality-assured assessment method in undergraduate education.MethodsOne hundred fifty-five students in their fifth year of medical school (78 videos) participated in a summative VOSCE within the framework of the teaching module “Operative Medicine.” They prepared for three clinical scenarios and the surgical procedures involved. The examination comprised participants having to obtain informed consent from simulated patients, video recording their performance. Students were assessed by two independent raters, the background of one of whom was nonsurgical. Results were statistically tested using SPSS.ResultsStudents' scores were all beyond the pass mark of 70%, averaging 91.0% (±4.0%), 88.4% (±4.4%), and 87.0% (±4.7%) for the appendectomy, cholecystectomy, and inguinal hernia repair checklist, respectively. Most items (68%–89% of the checklists) were found to have fair to excellent discrimination values. Cronbach's α values ranged between 0.565 and 0.605 for the individual checklists. Interrater agreement was strong (Pearson correlation coefficient = 0.80, P < 0.01; intraclass correlation coefficient 2.1 = 0.78).ConclusionsThe VOSCE is both feasible and reliable as a method of assessing student communication skills and the application of clinical knowledge while obtaining informed consent in surgery. This method is efficient (flexible rating outside normal working hours possible with reductions in administrative load) and may be used for high-stakes evaluation of student performance

Wiederverwendung von Geschäftsprozessmodellen durch Referenzmodellierung mit der SOM-Methodik

Durch die ständig ansteigende Komplexität von Softwaresystemen, den wachsenden Konkurrenzdruck in der Softwarebranche und die sich verkürzenden Produktlebenszyklen ist die Wiederverwendung bei der Anwendungssystementwicklung auch nach Jahrzehnten der Forschung ein aktuelles Thema. Ansätze zur Wiederverwendung zielen zumeist auf die Wiederverwendung von Entwicklungsergebnissen ab und führten in der Vergangenheit häufig nicht zur Erreichung der gewünschten Wiederverwendungsziele. Der Beitrag zeigt unter Verwendung von Entwurfs- und Strukturmustern Möglichkeiten auf, die über die Repräsentation von Problemlösungen hinausgehen und den Modellierer durch die Kapselung und Bereitstellung von Modellierungswissen in einem Referenzmodell umfassender in einer Wiederverwendungssituation unterstützen. Anhand eines Architekturrahmens für generische Referenzmodelle wird beispielhaft die Referenzmodellierung von Geschäftsprozessmodellen mit der SOM-Methodik aufgezeigt

Functionalization of P3HT with Various Mono- and Multidentate Anchor Groups

<div><p>Due to its favorable optoelectronic properties and the accessibility via Grignard metathesis (GRIM) polymerization, poly(3-hexylthiophene) (P3HT) is one of the most applied conjugated polymers. The ‘living' nature of GRIM polymerization enables the modification of the polymer and the installation of desired properties. In the present study, two versatile approaches for the synthesis of anchor group-modified P3HT have been developed, which enable the functionalization of various inorganic nanoparticles. Depending on the polymerization conditions, mono- and bifunctional ethynyl-terminated P3HT or solely monofunctionalized aldehyde-terminated P3HT was synthesized. Afterwards, the quantitative introduction of amine, mono- and multidentate disulfide and catechol anchor groups was performed by copper-catalyzed 1,3-dipolar cycloaddition or via imine formation reactions. The influence of the polymeric ligand structure on the functionalization of nanoparticles was then investigated for CdSe@ZnS quantum dots and TiO2 nanorods by transmission electron microscopy (TEM) and infrared (IR) spectroscopy.</p></div

Aspergillus specific nested PCR from the site of infection is superior to testing concurrent blood samples in immunocompromised patients with suspected invasive aspergillosis

Invasive aspergillosis (IA) is a severe complication in immunocompromised patients. Early diagnosis is crucial to decrease its high mortality, yet the diagnostic gold standard (histopathology and culture) is time-consuming and cannot offer early confirmation of IA. Detection of IA by polymerase chain reaction (PCR) shows promising potential. Various studies have analysed its diagnostic performance in different clinical settings, especially addressing optimal specimen selection. However, direct comparison of different types of specimens in individual patients though essential, is rarely reported. We systematically assessed the diagnostic performance of an Aspergillus-specific nested PCR by investigating specimens from the site of infection and comparing it with concurrent blood samples in individual patients (pts) with IA. In a retrospective multicenter analysis PCR was performed on clinical specimens (n = 138) of immunocompromised high-risk pts (n = 133) from the site of infection together with concurrent blood samples. 38 pts were classified as proven/probable, 67 as possible and 28 as no IA according to 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group consensus definitions. A considerably superior performance of PCR from the site of infection was observed particularly in pts during antifungal prophylaxis (AFP)/antifungal therapy (AFT). Besides a specificity of 85%, sensitivity varied markedly in BAL (64%), CSF (100%), tissue samples (67%) as opposed to concurrent blood samples (8%). Our results further emphasise the need for investigating clinical samples from the site of infection in case of suspected IA to further establish or rule out the diagnosis