Comparison of electromagnetic field solvers for the 3D analysis of plasmonic nano antennas

Plasmonic nano antennas are highly attractive at optical frequencies due to their strong resonances - even when their size is smaller than the wavelength - and because of their potential of extreme field enhancement. Such antennas may be applied for sensing of biological nano particles as well as for single molecule detection. Because of considerable material losses and strong dispersion of metals at optical frequencies, the numerical analysis of plasmonic antennas is very demanding. An additional difficulty is caused when very narrow gaps between nano particles are utilized for increasing the field enhancement. In this paper we discuss the main difficulties of time domain solvers, namely FDTD and FVTD and we compare various frequency domain solvers, namely the commercial FEM packages JCMsuite, Comsol, HFSS,and Microwave Studio with the semi-analytic MMP code that may be used as a reference due to its fast convergence and high accuracy.Comment: 12 pages, SPIE conference, Errata added on last pag

Sportwissenschaftliches Lehr-Lern-Labor "School goes BioMotion"

Einleitung: Zur Verbesserung der Qualität der Lehrerbildung werden im Rahmen des, durch das MWK Baden-Württemberg geförderte Verbundprojekt MINT2KA, bestehende Schüler- und Lehr-Lern-Labore (LLL) am Karlsruher Institut für Technologie und der Pädagogischen Hochschule Karlsruhe ausgebaut und weiterentwickelt. Teil dieses Projektes ist die Weiterentwicklung des LLLs von „School goes BioMotion“, das Schulklassen den Besuch von drei Laboreinrichtungen am Institut für Sport und Sportwissenschaft (KIT) ermöglicht. Organisation: In den ersten Einheiten des Hauptseminares „Theoriefelder der Naturwissenschaft“ werden den Studierenden fachdidaktische und forschungsspezifische Kenntnisse vermittelt und vorhandene Messsysteme vorgestellt. Die Studierenden erarbeiten im weiteren Verlauf ein Konzept für eine Lehr-Lern-Station (LLS). Dieses Konzept wird im Rahmen des Seminars erprobt, bevor es mit Schülerinnen und Schülern (SuS) durchgeführt wird. In einer abschließenden Einheit werden die Konzepte evaluiert und das eigene Lehrverhalten reflektiert. Stationen: Die im Seminar erarbeiteten LLS sind im Bereich der Biomechanik verortet. Als interdisziplinäres Fachgebiet finden verschiedene Methoden und Theorien anderer Wissenschaftsdisziplinen Beachtung - insbesondere die Physik (vgl. Schwameder et al., 2013, S. 125). Für die LLS wird der sportliche Kontext genutzt, um den SuS naturwissenschaftliche Inhalte zu vermitteln. Beispielsweise untersuchen die SuS in einer LLS die Möglichkeiten zur Optimierung der sportlichen Leistung im Radfahren. Mithilfe eines Fahrradergometers mit integriertem Pedalkraftmesssystem werden die auftretenden Kräfte während des Pedaltritts gemessen. Unter Berücksichtigung physikalischer Größen bei Kreisbewegungen leiten die SuS das Technikbild des „runden Tritts“ ab

A Semiquantitative Non-invasive Measurement of PcomA Patency in C57BL/6 Mice Explains Variance in Ischemic Brain Damage in Filament MCAo

Numerous studies on experimental ischemic stroke use the filament middle cerebral artery occlusion (fMCAo) model in C57BL/6 mice, but lesion sizes in this strain are highly variable. A known contributor is variation in the posterior communicating artery (PcomA) patency. We therefore aimed to provide a semiquantitative non-invasivein vivomethod to routinely assess PcomA patency. We included 43 male C57BL/6 mice from four independent studies using a transient 45 min fMCAo model. Edema-corrected lesion sizes were measured by magnetic resonance (MR) imaging 24 h after reperfusion. Time-of-flight MR angiography was performed 7 days before and 24 h after fMCAo. Scores of PcomA size measured 24 h after, but not scores measured 7 days before fMCAo were negatively correlated with lesion size. Variability in PcomA patency explained 30% of the variance in our cohort (p< 0.0001, coefficient of determinationr(2)= 0.3). In a simulation using parameters typical for experimental stroke research, the power to detect a true effect ofd= 1 between two groups increased by 15% when an according covariate was included in the statistical model. We have demonstrated thatin vivomeasurement of PcomA size is feasible and can lead to increased accuracy in assessing the effect of treatments

Plasma-assisted molecular beam epitaxy of SnO(001) films: Metastability, hole transport properties, Seebeck coefficient, and effective hole mass

Transparent conducting or semiconducting oxides are important materials for (transparent) optoelectronics and power electronics applications. While most of these oxides can be doped n-type only with room-temperature electron mobilities on the order of 100cm^2/Vs p-type oxides are needed for the realization of pn-junction devices but typically suffer from exessively low (<<1cm^2/Vs) hole mobilities. Tin monoxide (SnO) is one of the few p-type oxides with a higher hole mobility, lacking a well-established understanding of its hole transport properties. Moreover, growth of SnO is complicated by its metastability with respect to SnO2 and Sn, requiring epitaxy for the realization of single crystalline material typically required for high-end applications. Here, we give a comprehensive account on the epitaxial growth of SnO, its (meta)stability, and its thermoelectric transport properties in the context of the present literature. Textured and single-crystalline, unintentionally-doped p-type SnO(001) films are grown by plasma-assisted molecular beam epitaxy. The metastability of this semiconducting oxide is addressed theoretically through an equilibrium phase diagram. Experimentally, the related SnO growth window is rapidly determined by an in-situ growth kinetics study as function of Sn-to-O-plasma flux ratio and growth temperature. The presence of secondary Sn and SnOx (1 < x <= 2) phases is comprehensively studied by different methods, indicating the presence of Sn3O4 or Sn as major secondary phases, as well as a fully oxidized SnO2 film surface. The hole transport properties, Seebeck coefficient, and density-of-states effective mass are determined and critically discussed in the context of the present literature on SnO, considering its anisotropic hole-effective mass

Changes in gene expression patterns in the tumor microenvironment of head and neck squamous cell carcinoma under chemoradiotherapy depend on response

Chemoradiotherapy (CRT) is a standard treatment for advanced head and neck squamous cell carcinoma (HNSCC). Unfortunately, not all patients respond to this therapy and require further treatment, either salvage surgery or palliative therapy. The addition of immunotherapy to CRT is currently being investigated and early results describe a mixed response. Therefore, it is important to understand the impact of CRT on the tumor microenvironment (TME) to be able to interpret the results of the clinical trials. Paired biopsies from 30 HNSCC patients were collected before and three months after completion of primary CRT and interrogated for the expression of 1392 immune- and cancer-related genes. There was a relevant difference in the number of differentially expressed genes between the total cohort and patients with residual disease. Genes involved in T cell activation showed significantly reduced expression in these tumors after therapy. Furthermore, gene enrichment for several T cell subsets confirmed this observation. The analysis of tissue resident memory T cells (TRM) did not show a clear association with impaired response to therapy. CRT seems to lead to a loss of T cells in patients with incomplete response that needs to be reversed. It is not clear whether the addition of anti-PD-1 antibodies alone to CRT can prevent treatment failure, as no upregulation of the targets was measurable in the TME

Maternal synapsin autoantibodies are associated with neurodevelopmental delay

Maternal autoantibodies can be transmitted diaplacentally, with potentially deleterious effects on neurodevelopment. Synapsin 1 (SYN1) is a neuronal protein that is important for synaptic communication and neuronal plasticity. While monoallelic loss of function (LoF) variants in the SYN1 gene result in X-linked intellectual disability (ID), learning disabilities, epilepsy, behavioral problems, and macrocephaly, the effect of SYN1 autoantibodies on neurodevelopment remains unclear. We recruited a clinical cohort of 208 mothers and their children with neurologic abnormalities and analyzed the role of maternal SYN1 autoantibodies. We identified seropositivity in 9.6% of mothers, and seropositivity was associated with an increased risk for ID and behavioral problems. Furthermore, children more frequently had epilepsy, macrocephaly, and developmental delay, in line with the SYN1 LoF phenotype. Whether SYN1 autoantibodies have a direct pathogenic effect on neurodevelopment or serve as biomarkers requires functional experiments

DHTKD1 Mutations Cause 2-Aminoadipic and 2-Oxoadipic Aciduria

Abnormalities in metabolite profiles are valuable indicators of underlying pathologic conditions at the molecular level. However, their interpretation relies on detailed knowledge of the pathways, enzymes, and genes involved. Identification and characterization of their physiological function are therefore crucial for our understanding of human disease: they can provide guidance for therapeutic intervention and help us to identify suitable biomarkers for monitoring associated disorders. We studied two individuals with 2-aminoadipic and 2-oxoadipic aciduria, a metabolic condition that is still unresolved at the molecular level. This disorder has been associated with varying neurological symptoms. Exome sequencing of a single affected individual revealed compound heterozygosity for an initiating methionine mutation (c.1A>G) and a missense mutation (c.2185G>A [p.Gly729Arg]) in DHTKD1. This gene codes for dehydrogenase E1 and transketolase domain-containing protein 1, which is part of a 2-oxoglutarate-dehydrogenase-complex-like protein. Sequence analysis of a second individual identified the same missense mutation together with a nonsense mutation (c.1228C>T [p.Arg410∗]) in DHTKD1. Increased levels of 2-oxoadipate in individual-derived fibroblasts normalized upon lentiviral expression of the wild-type DHTKD1 mRNA. Moreover, investigation of L-lysine metabolism showed an accumulation of deuterium-labeled 2-oxoadipate only in noncomplemented cells, demonstrating that DHTKD1 codes for the enzyme mediating the last unresolved step in the L-lysine-degradation pathway. All together, our results establish mutations in DHTKD1 as a cause of human 2-aminoadipic and 2-oxoadipic aciduria via impaired turnover of decarboxylation 2-oxoadipate to glutaryl-CoA

Stable water isotopes and accumulation rates in the Union Glacier region, Ellsworth Mountains, West Antarctica, over the last 35 years

ntarctica is well known to be highly susceptible to atmospheric and oceanic warming. However, due to the lack of long-term and in situ meteorological observations, little is known about the magnitude of the warming and the meteorological conditions in the intersection region between the Antarctic Peninsula (AP), the West Antarctic Ice Sheet (WAIS) and the East Antarctic Ice Sheet (EAIS). Here we present new stable water isotope data (δ18O, δD, d excess) and accumulation rates from firn cores in the Union Glacier (UG) region, located in the Ellsworth Mountains at the northern edge of the WAIS. The firn core stable oxygen isotopes and the d excess exhibit no statistically significant trend for the period 1980–2014, suggesting that regional changes in near-surface air temperature and moisture source variability have been small during the last 35 years. Backward trajectory modelling revealed the Weddell Sea sector, Coats Land and Dronning Maud Land (DML) to be the main moisture source regions for the study site throughout the year. We found that mean annual δ18O (δD) values in the UG region are negatively correlated with sea ice concentrations (SICs) in the northern Weddell Sea but not influenced by large-scale modes of climate variability such as the Southern Annular Mode (SAM) and the El Niño–Southern Oscillation (ENSO). Only mean annual d-excess values show a weak positive correlation with the SAM. On average annual snow accumulation in the UG region amounts to 0.245 m w.e. a−1 in 1980–2014 and has slightly decreased during this period. It is only weakly related to sea ice conditions in the Weddell Sea sector and not correlated with SAM and ENSO. We conclude that neither the rapid warming nor the large increases in snow accumulation observed on the AP and in West Antarctica during the last decades have extended inland to the Ellsworth Mountains. Hence, the UG region, although located at the northern edge of the WAIS and relatively close to the AP, exhibits rather stable climate characteristics similar to those observed in East Antarctica

IntCal09 and Marine09 radiocarbon age calibration curves, 0-50,000yeats cal BP

The IntCal04 and Marine04 radiocarbon calibration curves have been updated from 12 cal kBP (cal kBP is here defined as thousands of calibrated years before AD 1950), and extended to 50 cal kBP, utilizing newly available data sets that meet the IntCal Working Group criteria for pristine corals and other carbonates and for quantification of uncertainty in both the 14C and calendar timescales as established in 2002. No change was made to the curves from 0–12 cal kBP. The curves were constructed using a Markov chain Monte Carlo (MCMC) implementation of the random walk model used for IntCal04 and Marine04. The new curves were ratified at the 20th International Radiocarbon Conference in June 2009 and are available in the Supplemental Material at www.radiocarbon.org