Dynamic Acoustic Control of Individual Optically Active Quantum Dot-like Emission Centers in Heterostructure Nanowires

We probe and control the optical properties of emission centers forming in radial het- erostructure GaAs-Al0.3Ga0.7As nanowires and show that these emitters, located in Al0.3Ga0.7As layers, can exhibit quantum-dot like characteristics. We employ a radio frequency surface acoustic wave to dynamically control their emission energy and occupancy state on a nanosec- ond timescale. In the spectral oscillations we identify unambiguous signatures arising from both the mechanical and electrical component of the surface acoustic wave. In addition, differ- ent emission lines of a single quantum dot exhibit pronounced anti-correlated intensity oscilla- tions during the acoustic cycle. These arise from a dynamically triggered carrier extraction out of the quantum dot to a continuum in the radial heterostructure. Using finite element modeling and Wentzel-Kramers-Brillouin theory we identify quantum tunneling as the underlying mech- anism. These simulation results quantitatively reproduce the observed switching and show that in our systems these quantum dots are spatially separated from the continuum by > 10.5 nm.Comment: This document is the unedited Author's version of a Submitted Work that was subsequently accepted for publication in Nano Letters, copyright \c{copyright} American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/nl404043

Factors influencing uptake of HPV vaccination among girls in Germany

Abstract Background Adequate coverage is key to the success of human papillomavirus (HPV) vaccination programmes. There is currently no organised HPV vaccination programme in Germany. The aim of this analysis was to determine HPV vaccine uptake as well as factors associated with uptake in nine to 17 year-old girls in Germany during the first year of vaccine availability. Methods This analysis is based on data from the Healthcare Access Panel, an established population-based household panel consisting of 55 000 representative households in Germany who were contacted between September and October 2007. A total of 4 747 households included at least one girl aged nine to 17 years. After reading a description of the HPV vaccine, these girls were asked, “Would you have yourself vaccinated against HPV?” Logistic regression analyses were performed to investigate associations between vaccination status and socio-demographic characteristics of the girls and their mothers. Results Of the 4 747 girls in the households who received questionnaires, 2 224 (46.9 %) participated in the study and 1 906 (40.2 %) answered the vaccination question. A total of 17.4 % of the girls were already vaccinated, 61.5 % felt positively about doing so, 4.7 % said they would not be vaccinated, and 16.3 % were not sure. The probability of a girl being vaccinated increased with each additional year of age (Odds Ratio (OR): 1.6, 95 % Confidence Interval (CI) 1.5–1.7). Among the 17 year-old girls, 38.5 % (95 % CI 32.6–44.4 %) had been vaccinated. Having a mother with high education (OR: 1.5, 95 % CI 1.0–2.3) or medium education (OR: 1.5, 95 % CI 1.1–2.1) versus basic education was a significant predictor for having been vaccinated. Similarly, medium (OR: 1.5, 95 % CI 1.0–2.4) versus low SES was significantly associated with having been vaccinated. Our analysis showed that during the first year of HPV vaccine availability in Germany, vaccination uptake was low. Conclusions Countries with organised HPV vaccination programmes showed much higher vaccination uptake, even in the first year after programme introduction. If vaccination uptake in Germany is to significantly improve in the future, an organised vaccination programme will need to be introduced

MYCN recruits the nuclear exosome complex to RNA polymerase II to prevent transcription-replication conflicts

The MYCN oncoprotein drives the development of numerous neuroendocrine and pediatric tumors. Here we show that MYCN interacts with the nuclear RNA exosome, a 3'-5' exoribonuclease complex, and recruits the exosome to its target genes. In the absence of the exosome, MYCN-directed elongation by RNA polymerase II (RNAPII) is slow and non-productive on a large group of cell-cycle-regulated genes. During the S phase of MYCN-driven tumor cells, the exosome is required to prevent the accumulation of stalled replication forks and of double-strand breaks close to the transcription start sites. Upon depletion of the exosome, activation of ATM causes recruitment of BRCA1, which stabilizes nuclear mRNA decapping complexes, leading to MYCN-dependent transcription termination. Disruption of mRNA decapping in turn activates ATR, indicating transcription-replication conflicts. We propose that exosome recruitment by MYCN maintains productive transcription elongation during S phase and prevents transcription-replication conflicts to maintain the rapid proliferation of neuroendocrine tumor cells

Tumour stage distribution and survival of malignant melanoma in Germany 2002-2011

Background Over the past two decades, there has been a rising trend in malignant melanoma incidence worldwide. In 2008, Germany introduced a nationwide skin cancer screening program starting at age 35. The aims of this study were to analyse the distribution of malignant melanoma tumour stages over time, as well as demographic and regional differences in stage distribution and survival of melanoma patients. Methods Pooled data from 61 895 malignant melanoma patients diagnosed between 2002 and 2011 and documented in 28 German population-based and hospital-based clinical cancer registries were analysed using descriptive methods, joinpoint regression, logistic regression and relative survival. Results The number of annually documented cases increased by 53.2% between 2002 (N = 4 779) and 2011 (N = 7 320). There was a statistically significant continuous positive trend in the proportion of stage UICC I cases diagnosed between 2002 and 2011, compared to a negative trend for stage UICC II. No trends were found for stages UICC III and IV respectively. Age (OR 0.97, 95% CI 0.97–0.97), sex (OR 1.18, 95% CI 1.11–1.25), date of diagnosis (OR 1.05, 95% CI 1.04–1.06), ‘diagnosis during screening’ (OR 3.24, 95% CI 2.50–4.19) and place of residence (OR 1.23, 95% CI 1.16–1.30) had a statistically significant influence on the tumour stage at diagnosis. The overall 5-year relative survival for invasive cases was 83.4% (95% CI 82.8–83.9%). Conclusions No distinct changes in the distribution of malignant melanoma tumour stages among those aged 35 and older were seen that could be directly attributed to the introduction of skin cancer screening in 2008.

Comparison of nine different commercially available molecular assays for detection of SARS-CoV-2 RNA

To face the COVID-19 pandemic, the need for fast and reliable diagnostic assays for the detection of SARS-CoV-2 is immense. We describe our laboratory experiences evaluating nine commercially available real-time RT-PCR assays. We found that assays differed considerably in performance and validation before routine use is mandatory

Additional file 4: Table S3. of Tumour stage distribution and survival of malignant melanoma in Germany 2002–2011

Relative 5-year survival of malignant melanoma patients diagnosed between 2002 and 2011, overall (UICC 0-IV, X) (N = 60 672) and for patients with invasive tumours (UICC I – IV, X) stratified by age, sex, UICC stage, ‘diagnosis during screening’ and place of residence (N = 49 351) (DOCX 39 kb