Ein Umschwung in den letzten Wochen des Landtagswahlkampfes: Befunde einer mehrwelligen Wiederholungsbefragung zur niedersächsischen Landtagswahl 2017

Die niedersächsische Landtagswahl im Oktober 2017 fand im Schatten der vorhergehenden Bundestagswahl statt. Vor dem Hintergrund der zeitlichen Nähe beider Wahlgänge untersucht dieser Aufsatz die Entwicklung bundes- und landesbezogener Einstellungen im Wahlkampfverlauf sowie deren Einfluss auf das Wählerverhalten in Niedersachsen. Eine mehrwellige Wiederholungsbefragung von 1.346 niedersächsischen Wahlberechtigten, die im Rahmen der German Longitudinal Election Study (GLES) durchgeführt wurde, dient als Grundlage der Untersuchung. In quer- und längsschnittlichen Analysen wird gezeigt, dass eine bedeutende Minderheit der Befragten den Wahlentscheidungen auf der Landesebene ebenenspezifische Erwägungen zu Grunde legt. Landesbezogene Einstellungen waren einer von der Bundesebene weitgehend unabhängigen Wahlkampfdynamik unterworfen, die die Wahlabsichten des Elektorats beeinflusst zu haben scheinen. So konnte gerade die niedersächsische SPD die Popularität ihres Spitzenkandidaten in den letzten Wahlkampfwochen steigern und dadurch die CDU in einem Schlussspurt als stärkste Kraft ablösen

MPI Phantom Study with A High-Performing Multicore Tracer Made by Coprecipitation

Magnetic particle imaging (MPI) is a new imaging technique that detects the spatial distribution of magnetic nanoparticles (MNP) with the option of high temporal resolution. MPI relies on particular MNP as tracers with tailored characteristics for improvement of sensitivity and image resolution. For this reason, we developed optimized multicore particles (MCP 3) made by coprecipitation via synthesis of green rust and subsequent oxidation to iron oxide cores consisting of a magnetite/maghemite mixed phase. MCP 3 shows high saturation magnetization close to that of bulk maghemite and provides excellent magnetic particle spectroscopy properties which are superior to Resovist® and any other up to now published MPI tracers made by coprecipitation. To evaluate the MPI characteristics of MCP 3 two kinds of tube phantoms were prepared and investigated to assess sensitivity, spatial resolution, artifact severity, and selectivity. Resovist® was used as standard of comparison. For image reconstruction, the regularization factor was optimized, and the resulting images were investigated in terms of quantifying of volumes and iron content. Our results demonstrate the superiority of MCP 3 over Resovist® for all investigated MPI characteristics and suggest that MCP 3 is promising for future experimental in vivo studies

Labeling of mesenchymal stem cells for MRI with single-cell sensitivity

Sensitive cell detection by magnetic resonance imaging (MRI) is an important tool for the development of cell therapies. However, clinically approved contrast agents that allow single-cell detection are currently not available. Therefore, we compared very small iron oxide nanoparticles (VSOP) and new multicore carboxymethyl dextran-coated iron oxide nanoparticles (multicore particles, MCP) designed by our department for magnetic particle imaging (MPI) with discontinued Resovist® regarding their suitability for detection of single mesenchymal stem cells (MSC) by MRI. We achieved an average intracellular nanoparticle (NP) load of .10 pg Fe per cell without the use of transfection agents. NP loading did not lead to significantly different results in proliferation, colony formation, and multilineage in vitro differentiation assays in comparison to controls. MRI allowed single-cell detection using VSOP, MCP, and Resovist® in conjunction with high-resolution T2*-weighted imaging at 7 T with postprocessing of phase images in agarose cell phantoms and in vivo after delivery of 2,000 NP-labeled MSC into mouse brains via the left carotid artery. With optimized labeling conditions, a detection rate of ~45% was achieved; however, the experiments were limited by nonhomogeneous NP loading of the MSC population. Attempts should be made to achieve better cell separation for homogeneous NP loading and to thus improve NP-uptake-dependent biocompatibility studies and cell detection by MRI and future MPI. Additionally, using a 7 T MR imager equipped with a cryocoil resulted in approximately two times higher detection. In conclusion, we established labeling conditions for new high-relaxivity MCP, VSOP, and Resovist® for improved MRI of MSC with single-cell sensitivity

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Lymphotoxin expression in human and murine renal allografts

The kidney is the most frequently transplanted solid organ. Recruitment of inflammatory cells, ranging from diffuse to nodular accumulations with defined microarchitecture, is a hallmark of acute and chronic renal allograft injury. Lymphotoxins (LTs) mediate the communication of lymphocytes and stromal cells and play a pivotal role in chronic inflammation and formation of lymphoid tissue. The aim of this study was to assess the expression of members of the LT system in acute rejection (AR) and chronic renal allograft injury such as transplant glomerulopathy (TG) and interstitial fibrosis/tubular atrophy (IFTA). We investigated differentially regulated components in transcriptomes of human renal allograft biopsies. By microarray analysis, we found the upregulation of LT beta, LIGHT, HVEM and TNF receptors 1 and 2 in AR and IFTA in human renal allograft biopsies. In addition, there was clear evidence for the activation of the NF kappa B pathway, most likely a consequence of LT beta receptor stimulation. In human renal allograft biopsies with transplant glomerulopathy (TG) two distinct transcriptional patterns of LT activation were revealed. By quantitative RT-PCR robust upregulation of LTa, LT beta and LIGHT was shown in biopsies with borderline lesions and AR. Immunohistochemistry revealed expression of LT beta in tubular epithelial cells and inflammatory infiltrates in transplant biopsies with AR and IFTA. Finally, activation of LT signaling was reproduced in a murine model of renal transplantation with AR. In summary, our results indicate a potential role of the LT system in acute renal allograft rejection and chronic transplant injury. Activation of the LT system in allograft rejection in rodents indicates a species independent mechanism. The functional role of the LT system in acute renal allograft rejection and chronic injury remains to be determined

New applications in ring rearrangement metathesis

Im ersten Teil der Arbeit wurden Versuche zur Ringumlagerungsmetathese mit gespannten Cycloolefinen durchgeführt. Hierzu wurden verschiedene Norbornenderivate mit olefinischen Seitenketten dargestellt, welche über eine Ringumlagerungsmetathese zu verschiedenen Carbocyclen führten. Es konnten ein [4.5]- und ein [4.6]-Spiran in mittleren bis guten Ausbeuten dargestellt werden. Die Versuche zur Darstellung der Carbocyclen führten lediglich in einem der zwei Fälle mit guten Ausbeuten zur Ringumlagerungsmetathese, im anderen Fall konnte keine Umsetzung erreicht werden. Weiterhin wurde eine Syntheseroute zur Darstellung von [2.2.2]-Tricyclooctenen mit olefinischen Seitenketten erarbeitet, welche in einer Ringumlagerungsmetathese zu [5.5]-Heterospiranen umgesetzt werden sollten. Die versuchten Umsetzungen mit den Metathesevorläufern führten jedoch nicht zum Erfolg. In einem weiteren Teil der Arbeit sollten Ringumlagerungsmetathesen mit Steroidderivaten durchgeführt werden. Es wurden ausgehend von kommerziell erhältlichen Steroiden, Metathesevorläufer dargestellt, die über eine anschließende Ringumlagerungsmetathese unter Öffnung des A-Rings, des B-Rings oder des D-Rings zu den entsprechenden Dihydrofuranen, Dehydropyranen, Dihydropyrol und Dehydropiperidinen umgesetzt werden sollten. Die Versuche zur Öffnung des A-Rings führten unter den getesteten Bedingungen bei keinem der Metathesevorläufern zu einer Ringumlagerungsmetathese. Das Steroid bei dem der B-Ring geöffnet werden sollte, ließ sich ebenfalls unter den Versuchsbedingungen nicht umsetzen. Bei den Versuchen zur Umlagerung des D-Rings gelangen mit einer Ausnahme alle Umsetzungen. Es konnten über En-En- und En-In- Ringumlagerungsmetathesen Dihydrofuranderivate in sehr guten Ausbeuten dargestellt werden. Des Weiteren wurden Sequenzen aus Ringumlagerungsmetathese und Kreuzmetathese in mittleren Ausbeuten durchgeführt

Just like leaves in the wind? Exploring the effect of the interplay of media coverage and personal characteristics on issue salience

This chapter explores the effect of the interplay of personal characteristics and news coverage on issue salience during the 2009 to 2015 period and during the election campaign in 2013. We selected four topics that played a considerable role during this period: the labor market, pensions and healthcare, immigration, and the financial crisis. The evidence from pooled cross-sectional data and panel data supports the notion that news coverage affects citizens’ issue salience. For obtrusive issues, news coverage does not play as large a role as for rather remote topics like the financial crisis and immigration. The results also lend credence to the idea that political predilections and other individual differences are related to issue salience and constrain the impact of news coverage on voters’ issue salience. However, the evidence for the interplay of individual differences and media coverage proved mild at best