3D Particle Track Reconstrution in a Single Layer Cadmium-Telluride Hybrid Active Pixel Detector

In the past 20 years the search for neutrinoless double beta decay has driven many developements in all kind of detector technology. A new branch in this field are highly-pixelated semiconductor detectors - such as the CdTe-Timepix detectors. It compromises a cadmium-telluride sensor of 14 mm x 14 mm x 1 mm size with an ASIC which has 256 x 256 pixel of 55 \textmu m pixel pitch and can be used to obtain either spectroscopic or timing information in every pixel. In regular operation it can provide a 2D projection of particle trajectories; however, three dimensional trajectories are desirable for neutrinoless double beta decay and other applications. In this paper we present a method to obtain such trajectories. The method was developed and tested with simulations that assume some minor modifications to the Timepix ASIC. Also, we were able to test the method experimentally and in the best case achieved a position resolution of about 90 \textmu m with electrons of 4.4 GeV.Comment: 10 pages, 15 figure

Extensive transcriptional complexity during hypoxia-regulated expression of the myoglobin gene in cancer

Recently, the ectopic expression of myoglobin (MB) was reported in human epithelial cancer cell lines and breast tumor tissues, where MB expression increased with hypoxia. The better prognosis of MB-positive breast cancer patients suggested that the globin exerts a tumor-suppressive role, possibly by impairing mitochondrial activity in hypoxic breast carcinoma cells. To better understand MB gene regulation in cancer, we systematically investigated the architecture of the human MB gene, its transcripts and promoters. In silico analysis of transcriptome data from normal human tissues and cancer cell lines, followed by RACE-PCR verification, revealed seven novel exons in the MB gene region, most of which are untranslated exons located 5′-upstream of the coding DNA sequence (CDS). Sixteen novel alternatively spliced MB transcripts were detected, most of which predominantly occur in tumor tissue or cell lines. Quantitative RT-PCR analyses of MB expression in surgical breast cancer specimen confirmed the preferential usage of a hitherto unknown, tumor-associated MB promoter, which was functionally validated by luciferase reporter gene assays. In line with clinical observations of MB up-regulation in avascular breast tumors, the novel cancer-associated MB splice variants exhibited increased expression in tumor cells subjected to experimental hypoxia. The novel gene regulatory mechanisms unveiled in this study support the idea of a non-canonical role of MB during carcinogenesi

Testes-specific hemoglobins in Drosophila evolved by a combination of sub- and neofunctionalization after gene duplication

<p>Abstract</p> <p>Background</p> <p>For a long time the presence of respiratory proteins in most insects has been considered unnecessary. However, in recent years it has become evident that globins belong to the standard repertoire of the insect genome. Like most other insect globins, the <it>glob1 </it>gene of <it>Drosophila melanogaster </it>displays a conserved expression pattern in the tracheae, the fat body and the Malpighian tubules.</p> <p>Results</p> <p>Here we show that the recently discovered <it>D. melanogaster </it>globin genes <it>glob2 </it>and <it>glob3 </it>both display an unusual male-specific expression in the reproductive tract during spermatogenesis. Both paralogs are transcribed at equivalent mRNA levels and largely overlap in their cellular expression patterns during spermatogenesis. Phylogenetic analyses showed that <it>glob2 </it>and <it>glob3 </it>reflect a gene duplication event that occurred in the ancestor of the <it>Sophophora </it>subgenus at least 40 million years ago. Therefore, flies of the <it>Drosophila </it>subgenus harbor only one <it>glob2/3</it>-like gene.</p> <p>Conclusions</p> <p>Phylogenetic and sequence analyses indicate an evolution of the <it>glob2 </it>and <it>glob3 </it>duplicates by a combination of sub- and neofunctionalization. Considering their restricted, testes-specific expression, an involvement of both globins in alleviating oxidative stress during spermatogenesis is conceivable.</p

Testes-specific hemoglobins in drosophila evolved by a combination of sub- and neofunctionalization after gene duplication

Background: For a long time the presence of respiratory proteins in most insects has bee

The Potential of Hybrid Pixel Detectors in the Search for the Neutrinoless Double-Beta Decay of Cd-116

We investigated the potential of the energy resolving hybrid pixel detector Timepix contacted to a CdTe sensor layer for the search for the neutrinoless double-beta decay of Cd-116. We found that a CdTe sensor layer with 3 mm thickness and 165 mu m pixel pitch is optimal with respect to the effective Majorana neutrino mass (m(beta beta)) sensitivity. In simulations, we were able to demonstrate a possible reduction of the background level caused by single electrons by approximately 75% at a specific background rate of 10(-3) counts/(kg x keV x yr) at a detection efficiency reduction of about 23% with track analysis employing random decision forests. Exploitation of the imaging properties with track analysis leads to an improvement in sensitivity to m(beta beta) by about 22%. After 5 years of measuring time, the sensitivity to m(beta beta) of a 420 kg CdTe experiment (90% Cd-116 enrichment) would be 59 meV on a 90% confidence level for a specific single-electron background rate of 10(-3) counts/(kg x keV x yr). The alpha-particle background can be suppressed by at least about six orders of magnitude. The benefit of the hybrid pixel detector technology might be increased significantly if drift-time difference measurements would allow reconstruction of tracks in three dimensions

Three dimensional photograph of single electron tracks through a scintillator

The reconstruction of particle trajectories makes it possible to distinguish between different types of charged particles. In high-energy physics, where trajectories are rather long, large size trackers must be used to achieve sufficient position resolution. However, in low-background experiments tracks are rather short and three dimensional trajectories could only be resolved in time-projection chambers so far. For detectors of large volume and therefore large drift distances, which are inevitable for low-background experiments, this technique is limited by diffusion of charge carriers. In this work we present a "proof-of-principle" experiment for a new method for the three dimensional tracking of charged particles by scintillation light: We used a setup consisting of a scintillator, mirrors, lenses and a novel imaging device (the hybrid photo detector) in order to image two projections of electron tracks through the scintillator. We took data at the T-24 beam-line at DESY with relativistic electrons with a kinetic energy of 5 GeV and from this data successfully reconstructed their three dimensional propagetion path in the scintillator. With our setup we achieved a position resolution of about 28 mum in the best case.Comment: 9 pages, 13 figures, 1 tabl

Detection of non-classical space-time correlations with a novel type of single-photon camera

During the last decades, multi-pixel detectors have been developed capable of registering single photons. The newly developed Hybrid Photon Detector camera has a remarkable property that it has not only spatial but also temporal resolution. In this work, we use this device for the detection of non-classical light from spontaneous parametric down-conversion and use two-photon correlations for the absolute calibration of its quantum efficiency

Duration of invasive mechanical ventilation prior to extracorporeal membrane oxygenation is not associated with survival in acute respiratory distress syndrome caused by coronavirus disease 2019

BACKGROUND: Duration of invasive mechanical ventilation (IMV) prior to extracorporeal membrane oxygenation (ECMO) affects outcome in acute respiratory distress syndrome (ARDS). In coronavirus disease 2019 (COVID-19) related ARDS, the role of pre-ECMO IMV duration is unclear. This single-centre, retrospective study included critically ill adults treated with ECMO due to severe COVID-19-related ARDS between 01/2020 and 05/2021. The primary objective was to determine whether duration of IMV prior to ECMO cannulation influenced ICU mortality. RESULTS: During the study period, 101 patients (mean age 56 [SD ± 10] years; 70 [69%] men; median RESP score 2 [IQR 1–4]) were treated with ECMO for COVID-19. Sixty patients (59%) survived to ICU discharge. Median ICU length of stay was 31 [IQR 20.7–51] days, median ECMO duration was 16.4 [IQR 8.7–27.7] days, and median time from intubation to ECMO start was 7.7 [IQR 3.6–12.5] days. Fifty-three (52%) patients had a pre-ECMO IMV duration of > 7 days. Pre-ECMO IMV duration had no effect on survival (p = 0.95). No significant difference in survival was found when patients with a pre-ECMO IMV duration of < 7 days (< 10 days) were compared to ≥ 7 days (≥ 10 days) (p = 0.59 and p = 1.0). CONCLUSIONS: The role of prolonged pre-ECMO IMV duration as a contraindication for ECMO in patients with COVID-19-related ARDS should be scrutinised. Evaluation for ECMO should be assessed on an individual and patient-centred basis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13613-022-00980-3

Eyes on the future – evidence for trade‐offs between growth, storage and defense in Norway spruce

Carbon (C) allocation plays a central role in tree responses to environmental changes. Yet, fundamental questions remain about how trees allocate C to different sinks, for example, growth vs storage and defense. In order to elucidate allocation priorities, we manipulated the whole‐tree C balance by modifying atmospheric CO2 concentrations [CO2] to create two distinct gradients of declining C availability, and compared how C was allocated among fluxes (respiration and volatile monoterpenes) and biomass C pools (total biomass, nonstructural carbohydrates (NSC) and secondary metabolites (SM)) in well‐watered Norway spruce (Picea abies) saplings. Continuous isotope labelling was used to trace the fate of newly‐assimilated C. Reducing [CO2] to 120 ppm caused an aboveground C compensation point (i.e. net C balance was zero) and resulted in decreases in growth and respiration. By contrast, soluble sugars and SM remained relatively constant in aboveground young organs and were partially maintained with a constant allocation of newly‐assimilated C, even at expense of root death from C exhaustion. We conclude that spruce trees have a conservative allocation strategy under source limitation: growth and respiration can be downregulated to maintain ‘operational’ concentrations of NSC while investing newly‐assimilated C into future survival by producing SM.Supplementary material: Fig. S1 Concentrations of soluble sugars, starch and NSC (soluble sugars + starch) expressed as percentage of control (400 ppm [CO2]) at the whole‐tree level. Fig. S2 Concentrations of soluble sugars, starch and NSC (soluble sugars + starch) at the whole‐tree level. Fig. S3 Concentrations of phenolic compounds, monoterpenes and total secondary metabolites expressed as percentage of control (400 ppm [CO2]) at the whole‐tree level. Fig. S4 Concentrations of phenolic compounds, monoterpenes and total secondary metabolites (phenolic compounds + monoterpenes) at the whole‐tree level. Fig. S5 δ13C (‰) of bulk tissue, water soluble C and phenolic compounds at the whole‐tree level. Methods S1 TD‐GC‐MS conditions for BVOC analysis. Table S1 Internal standards, weight‐based response factors and methods used for the measurements of secondary metabolites. Table S2 A rough estimation of allocation of newly‐assimilated carbon.JH was funded by the Chinese Scholarship Council and Max Planck Institute for Biogeochemistry, and acknowledges support from the International Max Planck Research School for Global Biogeochemical Cycles.http://www.newphytologist.com2020-04-01hj2019Forestry and Agricultural Biotechnology Institute (FABI)Zoology and Entomolog