Trapping of C2− in a digital ion trap Hinterberger, Alexander; Gerber, Sebastian; Oswald, Emanuel ...
Journal of physics. B, Atomic, molecular, and optical physics,
10/2019, Letnik:
52, Številka:
22
Journal Article
Recenzirano
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In this article we present the production of a pulsed molecular C2− beam and the subsequent trapping of C2− in a digital ion trap (DIT). The anionic molecules were produced in a pulsed discharge ...valve from acetylene and carbon dioxide gas in a helium carrier. The mass spectrum of the pulsed anion beam is initially recorded using a Wien filter. Subsequently, we measured the mass spectrum using the DIT and its stability diagram. The results are compared to a theoretical description of the trap's stability conditions. The research is relevant for future laser cooling experiments of trapped C2− and for sympathetic cooling experiments of other anionic species (antiprotons, electrons, anionic atoms and molecules) and are of interest for precision experiments on antihydrogen as performed at the antiproton decelerator facility at CERN.
Pulsed production of antihydrogen Amsler, Claude; Antonello, Massimiliano; Belov, Alexander ...
Communications physics,
01/2021, Letnik:
4, Številka:
1
Journal Article
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Abstract
Antihydrogen atoms with K or sub-K temperature are a powerful tool to precisely probe the validity of fundamental physics laws and the design of highly sensitive experiments needs ...antihydrogen with controllable and well defined conditions. We present here experimental results on the production of antihydrogen in a pulsed mode in which the time when 90% of the atoms are produced is known with an uncertainty of ~250 ns. The pulsed source is generated by the charge-exchange reaction between Rydberg positronium atoms—produced via the injection of a pulsed positron beam into a nanochanneled Si target, and excited by laser pulses—and antiprotons, trapped, cooled and manipulated in electromagnetic traps. The pulsed production enables the control of the antihydrogen temperature, the tunability of the Rydberg states, their de-excitation by pulsed lasers and the manipulation through electric field gradients. The production of pulsed antihydrogen is a major landmark in the AE
$$\bar{g}$$
ḡ
IS experiment to perform direct measurements of the validity of the Weak Equivalence Principle for antimatter.
We describe a multi-step “rotating wall” compression of a mixed cold antiproton–electron non-neutral plasma in a 4.46 T Penning–Malmberg trap developed in the context of the AEḡIS experiment at ...CERN. Such traps are routinely used for the preparation of cold antiprotons suitable for antihydrogen production. A tenfold antiproton radius compression has been achieved, with a minimum antiproton radius of only 0.17 mm. We describe the experimental conditions necessary to perform such a compression: minimizing the tails of the electron density distribution is paramount to ensure that the antiproton density distribution follows that of the electrons. Such electron density tails are remnants of rotating wall compression and in many cases can remain unnoticed. We observe that the compression dynamics for a pure electron plasma behaves the same way as that of a mixed antiproton and electron plasma. Thanks to this optimized compression method and the high single shot antiproton catching efficiency, we observe for the first time cold and dense non-neutral antiproton plasmas with particle densities
n
≥ 10
13
m
−3
, which pave the way for an efficient pulsed antihydrogen production in AEḡIS.
Graphical abstract
This correction provides updated acknowledgements:
This work was supported by Istituto Nazionale di Fisica Nucleare; the Swiss National Science Foundation Ambizione Grant (No. 154833); a Deutsche ...Forschungsgemeinschaft research grant; an excellence initiative of Heidelberg University; Marie Sklodowska-Curie Innovative Training Network Fellowship of the European Commission’s Horizon 2020 Programme (No. 721559 AVA); European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement ANGRAM No 748826; European Research Council under the European Union’s Seventh Framework Program FP7/2007-2013 (Grants Nos. 291242 and 277762); Austrian Ministry for Science, Research, and Economy; Research Council of Norway; Bergen Research Foundation; John Templeton Foundation; Ministry of Education and Science of the Russian Federation and Russian Academy of Sciences; and the European Social Fund within the framework of realizing the project, in support of intersectoral mobility and quality enhancement of research teams at Czech Technical University in Prague (Grant No. CZ.1.07/2.3.00/30.0034).
This correction provides updated acknowledgements:This work was supported by Istituto Nazionale di Fisica Nucleare; the Swiss National Science Foundation Ambizione Grant (No. 154833); a Deutsche ...Forschungsgemeinschaft research grant; an excellence initiative of Heidelberg University; Marie Sklodowska-Curie Innovative Training Network Fellowship of the European Commission’s Horizon 2020 Programme (No. 721559 AVA); European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement ANGRAM No 748826; European Research Council under the European Union’s Seventh Framework Program FP7/2007-2013 (Grants Nos. 291242 and 277762); Austrian Ministry for Science, Research, and Economy; Research Council of Norway; Bergen Research Foundation; John Templeton Foundation; Ministry of Education and Science of the Russian Federation and Russian Academy of Sciences; and the European Social Fund within the framework of realizing the project, in support of intersectoral mobility and quality enhancement of research teams at Czech Technical University in Prague (Grant No. CZ.1.07/2.3.00/30.0034).
Imaging a positronium cloud in a 1 Tesla Camper, Antoine; Aghion, Stefano; Amsler, Claude ...
EPJ Web of Conferences,
2019, Letnik:
198
Journal Article, Conference Proceeding
Recenzirano
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We report on recent developments in positronium work in the frame of antihydrogen production through charge exchange in the AEgIS collaboration 1. In particular, we present a new technique based on ...spatially imaging a cloud of positronium by collecting the positrons emitted by photoionization. This background free diagnostic proves to be highly efficient and opens up new opportunities for spectroscopy on antimatter, control and laser manipulation of positronium clouds as well as Doppler velocimetry.
The induction of antiviral innate immunity by systemic immunization with live virus can be employed to positively impact the response to therapeutic vaccination. We previously demonstrated that ...systemic immunization with a non-replicating MVA encoding CD40 ligand (CD40L) enhances innate immune cell activation and function, and triggers potent antitumor CD8
T cell responses in different murine tumor models. Antitumor efficacy was increased when combined with tumor targeting antibodies. Here we report the development of TAEK-VAC-HerBy (TVH), a first-in-class human tumor antibody enhanced killing (TAEK) vaccine based on the non-replicating MVA-BN viral vector. It encodes the membrane bound form of human CD40L, HER2 and the transcription factor Brachyury. TVH is designed for therapeutic use in HER2- or Brachyury-expressing cancer patients in combination with tumor targeting antibodies. To preclude possible oncogenic activities in infected cells and to prevent binding of vaccine-encoded HER2 by monoclonal antibodies trastuzumab and pertuzumab, genetic modifications of HER2 were introduced in the vaccine. Brachyury was genetically modified to prevent nuclear localization of the protein thereby inhibiting its transcriptional activity. CD40L encoded in TVH enhanced human leukocyte activation and cytokine secretion in vitro. Lastly, TVH intravenous administration to non-human primates was proven immunogenic and safe in a repeat-dose toxicity study. Nonclinical data presented here highlight TVH as a first-in-class immunotherapeutic vaccine platform currently under clinical investigation.
Research suggests that stays in a forest promote relaxation and reduce stress compared to spending time in a city. The aim of this study was to compare stays in a forest with another natural ...environment, a cultivated field. Healthy, highly sensitive persons (HSP, SV12 score > 18) aged between 18 and 70 years spent one hour in the forest and in the field at intervals of one week. The primary outcome was measured using the Change in Subjective Self-Perception (CSP-14) questionnaire. Secondary outcomes were measured using the Profile Of Mood States (POMS) questionnaire and by analyzing salivary cortisol. We randomized 43 participants. Thirty-nine were allocated and included in the intention-to-treat analysis (90% female, mean age 45 years). CSP-14 in part showed significant differences-total score (
= 0.054, Cohen's d = 0.319), item "integration" (
= 0.028, Cohen's d = 0.365)-favoring the effects of the forest. These effects were more pronounced in summer (August). In October, during rainfall, we detected no relevant differences. POMS only showed a significant difference in the subcategory "depression/anxiety" in favor of the field. The amount of cortisol in saliva was not different between the groups. A short-term stay in a forest in summer caused a greater improvement in mood and well-being in HSP than in a field. This effect was not detectable during bad weather in the fall.
The H3K9me3-specific histone methyltransferase Setdb1 impacts on transcriptional regulation by repressing both developmental genes and retrotransposons. How impaired retrotransposon silencing may ...lead to developmental phenotypes is currently unclear. Here, we show that loss of Setdb1 in pro-B cells completely abrogates B cell development. In pro-B cells, Setdb1 is dispensable for silencing of lineage-inappropriate developmental genes. Instead, we detect strong derepression of endogenous murine leukemia virus (MLV) copies. This activation coincides with an unusual change in chromatin structure, with only partial loss of H3K9me3 and unchanged DNA methylation, but strongly increased H3K4me3. Production of MLV proteins leads to activation of the unfolded protein response pathway and apoptosis. Thus, our data demonstrate that B cell development depends on the proper repression of retrotransposon sequences through Setdb1.
•In a population of non-institutionalized 75 years-old subjects, lncRNA H19 predicts all-cause mortality over a follow-up of 14 years.•lncRNA H19 is differentially expressed in males and females, and ...it is a possible feature of sex differences in lifespan.•low-levels of lncRNA NKILA are associated with an increased risk of lacunar stroke, detected by magnetic resonance, over a follow-up of 7.5 years.
Differential expression of long non-coding RNAs (lncRNAs) is a hallmark of cardiovascular aging, cerebrovascular diseases, and neurodegenerative disorders. This research article investigates the association between a panel of lncRNAs and the risk of death and ischemic stroke in a cohort of non-institutionalized elderly subjects.
A total of 361 healthy individuals aged 75 years old, prospectively recruited in the Vienna Transdanube Aging (VITA) cohort, were included. Expression of lncRNAs at baseline was assessed using quantitative polymerase chain reaction PCR with pre-amplification reaction, using 18S for normalization. The primary endpoint was all-cause mortality; the secondary endpoint was the incidence of new ischemic brain lesions. Death was assessed over a 14-year follow-up, and ischemic brain lesions were evaluated by magnetic resonance imaging (MRI) over a 90-month follow-up. Ischemic brain lesions were divided into large brain infarcts (Ø≥ 1.5 cm) or lacunes (Ø< 1.5 cm)
The primary endpoint occurred in 53.5 % of the study population. The incidence of the secondary endpoint was 16 %, with a 3.3 % being large brain infarcts, and a 12.7 % lacunes.
After adjustment for potential confounders, the lncRNA H19 predicted the incidence of the primary endpoint (HR 1.194, 95 % C.I. 1.012–1.409, p = 0.036), whereas the lncRNA NKILA was associated with lacunar stroke (HR 0.571, 95 % C.I. 0.375–0.868, p = 0.006).
In a prospective cohort of non-institutionalized elderly subjects, high levels of lncRNA H19 are associated with a higher risk of death, while low levels of lncRNA NKILA predict an increased risk of lacunar stroke.
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