753 research outputs found
Monolithic HV-CMOS sensors for a beam monitoring system of therapeutic ion beams
Nowadays, cancer treatment with ion beam is well established and studied. This method allows to deposit the maximum dose to the tumor and minimize the damage to healthy tissue, due to the Bragg peak of the ion energy deposition near the end of the particle range. During the treatment, it is possible to provide volumetric dose delivery by changing the particle energy (penetration depth) and adjusting the beam position via a magnetic system. For the beam monitoring system, the precise measurement of the beam direction, shape and fluence in real time becomes crucial to provide effective and safe dose delivery to the tumor. Additionally, the system should work for beam intensities up to 10 s for protons, be tolerant to 1 MeV neutron equivalent fluences up to 10 cm per year and be to tolerant to magnetic fields (for MR-guided ion beam). The studies presented in this article are focused on the application of the HitPix sensor family with counting electronics and frame-based readout for such a beam monitoring system. The HitPix sensors are monolithic pixelated silicon sensors based on HV-CMOS technology and have been developed at the ASIC and Detector Lab (ADL, KIT). Recent measurements with ion beams and a multi-sensor readout as well as future developments are discussed
Epigenetic Modulators Link Mitochondrial Redox Homeostasis to Cardiac Function in a Sex-Dependent Manner
While excessive production of reactive oxygen species (ROS) is a characteristic hallmark of numerous diseases, clinical approaches that ameliorate oxidative stress have been unsuccessful. Here, utilizing multi-omics, we demonstrate that in cardiomyocytes, mitochondrial isocitrate dehydrogenase (IDH2) constitutes a major antioxidative defense mechanism. Paradoxically reduced expression of IDH2 associated with ventricular eccentric hypertrophy is counterbalanced by an increase in the enzyme activity. We unveil redox-dependent sex dimorphism, and extensive mutual regulation of the antioxidative activities of IDH2 and NRF2 by a feedforward network that involves 2-oxoglutarate and L-2-hydroxyglutarate and mediated in part through unconventional hydroxy-methylation of cytosine residues present in introns. Consequently, conditional targeting of ROS in a murine model of heart failure improves cardiac function in sex- and phenotype-dependent manners. Together, these insights may explain why previous attempts to treat heart failure with antioxidants have been unsuccessful and open new approaches to personalizing and, thereby, improving such treatment
Influence of soil on the efficacy of entomopathogenic nematodes in reducing Diabrotica virgifera virgifera in maize
The use of entomopathogenic nematodes is one potential non-chemical approach to control the larvae of the invasive western corn rootworm (Diabrotica virgifera virgifera LeConte, Coleoptera: Chrysomelidae) in Europe. This study investigated the efficacy of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), Heterorhabditis megidis Poinar, Jackson and Klein (Rh., Heterorhabditidae) and Steinernema feltiae Filipjev (Rh., Steinernematidae) in reducing D. v. virgifera as a function of soil characteristics. A field experiment was repeated four times in southern Hungary using artificially infested maize plants potted into three different soils. Sleeve gauze cages were used to assess the number of emerging adult D. v. virgifera from the treatments and untreated controls. Results indicate that nematodes have the potential to reduce D. v. virgifera larvae in most soils; however, their efficacy can be higher in maize fields with heavy clay or silty clay soils than in sandy soils, which is in contrast to the common assumption that nematodes perform better in sandy soils than in heavy soils
Subterranean, herbivore-induced plant volatile increases biological control activity of multiple beneficial nematode species in distinct habitats
While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs). However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene) from citrus roots 9-12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus) compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis) again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests.info:eu-repo/semantics/publishedVersio
Risk assessment of toxins derived from Bacillus thuringiensisâsynergism, efficacy, and selectivity
Local host-dependent persistence of the entomopathogenic nematode Steinernema carpocapsae used to control the large pine weevil Hylobius abietis
Entomopathogenic nematodes (EPN) applied inundatively to suppress insect pests are more likely to persist and establish in stable agroecosystems than in annual crops. We investigated a system of intermediate stability: three stumps harbouring the large pine weevil (Hylobius abietis L.; Coleoptera: Curculionidae), a major European forestry pest. We tested whether persistence of EPN Steinernema carpocapsae Weiser (Rhabditida: Steinernematidae) applied around stumps is maintained by recycling of EPN through pine weevils developing within stumps. Steinernema carpocapsae was detected in soil around and under the bark of treated tree stumps up to two years, but not 4â5 years after application. Differences in nematode presence between sites were better explained by tree species (pine or spruce) than soil type (mineral or peat). Presence of S. carpocapsae in soil was positively correlated with the number of H. abietis emerging from untreated stumps the previous year, which was greater for pine stumps than spruce stumps
Search for the lepton flavor violating decay Ï â 3ÎŒ in proton-proton collisions at = 13 TeV
Results are reported from a search for the lepton flavor violating decay Ï â 3ÎŒ in proton-proton collisions at = 13 TeV. The data sample corresponds to an integrated luminosity of 33.2 fb recorded by the CMS experiment at the LHC in 2016. The search exploits Ï leptons produced in both W boson and heavy-flavor hadron decays. No significant excess above the expected background is observed. An upper limit on the branching fraction B(Ï â 3ÎŒ) of 8.0 x 10 at 90% confidence level is obtained, with an expected upper limit of 6.9 x 10
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