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Background: The rise in asthma has been linked to different environmental and lifestyle factors including dietary habits. Whether dietary salt contributes to asthma incidence, remains controversial. We aimed to investigate the impact of higher salt intake on asthma incidence in humans and to evaluate underlying mechanisms using mouse models. Methods: Epidemiological research was conducted using the UK Biobank Resource. Data were obtained from 42,976 participants with a history of allergies. 24‐h sodium excretion was estimated from spot urine, and its association with asthma incidence was assessed by Cox regression, adjusting for relevant covariates. For mechanistic studies, a mouse model of mite‐induced allergic airway inflammation (AAI) fed with high‐salt diet (HSD) or normal‐salt chow was used to characterize disease development. The microbiome of lung and feces (as proxy for gut) was analyzed via 16S rRNA gene based metabarcoding approach. Results: In humans, urinary sodium excretion was directly associated with asthma incidence among females but not among males. HSD‐fed female mice displayed an aggravated AAI characterized by increased levels of total IgE, a TH2‐TH17‐biased inflammatory cell infiltration accompanied by upregulation of osmosensitive stress genes. HSD induced distinct changes in serum short chain fatty acids and in both gut and lung microbiome, with a lower Bacteroidetes to Firmicutes ratio and decreased Lactobacillus relative abundance in the gut, and enriched members of Gammaproteobacteria in the lung. Conclusions: High dietary salt consumption correlates with asthma incidence in female adults with a history of allergies. Female mice revealed HSD‐induced T‐cell lung profiles accompanied by alterations of gut and lung microbiome. [ABSTRACT FROM AUTHOR]

One limiting factor in progress in the discovery and study of new superheavy elements (SHE) is the maximum achievable thickness and irradiation stability of current generation actinide targets. The desired thickness of targets, using full excitation function widths, cannot be achieved with current target technology, especially the widely used molecular plating (MP). The aim of this study was to transfer progress in the electrochemistry of lanthanides and actinides to the production of targets. Here, we report on the production of lanthanide targets using anhydrous electrochemical routes. In a first irradiation series, thulium thin films with areal densities up to 1800 μg/cm2 were produced using anhydrous triflate compounds and subjected to irradiation tests, using 6.0 MeV/u 48Ca ions at a fluence of 3.9 × 1014 ions/cm2 and 8.6 MeV/u 197Au ions at fluences in the range of 3.0 × 1011 to 1.0 × 1013 ions/cm2. The thin films were characterised before and after the irradiations using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). [ABSTRACT FROM AUTHOR]

We give an overview of the special challenges regarding target development and production for accelerator-based heavy and superheavy-nuclei experiments in the past and perspectives for the future. Production of ever heavier elements, studies of heavy-element production in fusion or transfer reactions, spectroscopic investigations on their nuclear structure and decay and on the fission processes with fragment analyses, laser spectroscopic studies of their atomic structure, high-precision mass measurements as well as chemical studies are lively fields of current science. The ever-increasing beam intensities, feasible with new accelerator development, are crucial for the synthesis of superheavy elements because of the low cross sections for many of the reactions. Therefore, the development of target and backing materials with higher durability and experiment lifetime is increasingly important. Here we concentrate on the techniques necessary for the production of targets that are needed for experiments in this special field of interest. For the future, also development on target monitoring, target cooling, and beam intensity profile shaping techniques will play an important role, but are not in the focus of this article. [ABSTRACT FROM AUTHOR]

Superheavy element research has been a strong pillar of the research program at GSI Darmstadt since its foundation. Six new elements were discovered along with many new isotopes. Initial results on chemical properties of the heaviest elements were obtained that allowed for comparing their behavior with that of their lighter homologs and with theoretical predictions. Main achievements of the past five decades of superheavy element research at GSI are described along with an outlook into the future of superheavy element research in Darmstadt. [ABSTRACT FROM AUTHOR]

The formation of carbonyl complexes using atom-at-a-time quantities of short-lived transition metals from fusion and fission reactions was reported in 2012. Numerous studies focussing on this chemical system, which is also applicable for the superheavy elements followed. We report on a novel two-chamber approach for the synthesis of such complexes that allows spatial decoupling of thermalization and gas-phase carbonyl complex synthesis. Neutron induced fission on 235U and spontaneous fission of 248Cm were employed for the production of the fission products. These were stopped inside a gas volume behind the target and flushed with an inert-gas flow into a second chamber. This was flushed with carbon monoxide to allow the gas-phase synthesis of carbonyl complexes. Parameter studies of the transfer from the first into the second chamber as well as on the carbonyl complex formation and transport processes have been performed. High overall efficiencies of more than 50% were reached rendering this approach interesting for studies of superheavy elements. Our results show that carbonyl complex formation of thermalized fission products is a single-atom reaction, and not a hot-atom reaction. [ABSTRACT FROM AUTHOR]

Four different techniques were applied for the production of 233U alpha recoil ion sources, providing 229Th ions. They were compared with respect to a minimum energy spread of the 229Th recoil ions, using the emitted alpha particles as an indicator. The techniques of Molecular Plating, Drop-on-Demand inkjet printing, chelation from dilute nitric acid solution on chemically functionalized silicon surfaces, and self-adsorption on passivated titanium surfaces were used. All fabricated sources were characterized by using alpha spectrometry, radiographic imaging, and scanning electron microscopy. A direct validation for the estimated recoil ion rate was obtained by collecting 228Th recoil ions from 232U recoil ion sources prepared by self-adsorption and Molecular Plating. The chelation and the self-adsorption based approaches appear most promising for the preparation of recoil ion sources delivering monochromatic recoil ions. [ABSTRACT FROM AUTHOR]

The masses of the lightest atomic nuclei and the electron mass1 are interlinked, and their values affect observables in atomic2, molecular3–5 and neutrino physics6, as well as metrology. The most precise values for these fundamental parameters come from Penning trap mass spectrometry, which achieves relative mass uncertainties of the order of 10−11. However, redundancy checks using data from different experiments reveal considerable inconsistencies in the masses of the proton, the deuteron and the helion (the nucleus of helium-3), suggesting that the uncertainty of these values may have been underestimated. Here we present results from absolute mass measurements of the deuteron and the HD+ molecular ion using 12C as a mass reference. Our value for the deuteron mass, 2.013553212535(17) atomic mass units, has better precision than the CODATA value7 by a factor of 2.4 and differs from it by 4.8 standard deviations. With a relative uncertainty of eight parts per trillion, this is the most precise mass value measured directly in atomic mass units. Furthermore, our measurement of the mass of the HD+ molecular ion, 3.021378241561(61) atomic mass units, not only allows a rigorous consistency check of our results for the masses of the deuteron (this work) and the proton8, but also establishes an additional link for the masses of tritium9 and helium-3 (ref. 10) to the atomic mass unit. Combined with a recent measurement of the deuteron-to-proton mass ratio11, the uncertainty of the reference value of the proton mass7 can be reduced by a factor of three. Penning trap mass spectrometry is used to measure the masses of the deuteron and the HD+ ion with unprecedented precision, reducing the uncertainty of the proton mass reference value. [ABSTRACT FROM AUTHOR]

Ions of the isomer 229mTh are a topic of high interest for the construction of a "nuclear clock" and in the field of fundamental physics for testing symmetries of nature. They can be efficiently captured in Paul traps which are ideal for performing high precision quantum logic spectroscopy. Trapping and identification of long-lived 232Th+ ions from a laser ablation source was already demonstrated by the TACTICa collaboration on Trapping And Cooling of Thorium Ions with Calcium. The 229mTh is most easily accessible as α-decay daughter of the decay of 233U. We report on the development of a source for slow Th ions, including 229mTh for the TACTICa experiment. The 229mTh source is currently under construction and comprises a 233U monolayer, from which 229mTh ions recoil. These are decelerated in an electric field. Conservation of the full initial charge state distribution of the 229mTh recoil ions is one of the unique features of this source. We present ion-flight simulations for our adopted layout and give a final source design. This source will provide Th ions in their original charge state at energies suitable for capture in a linear Paul trap for spectroscopy investigations. [ABSTRACT FROM AUTHOR]

The Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is a powerful, highly reliable and selective reaction which allows for a rapid synthesis in high yields and under mild conditions (pH, temperature). However, the cytotoxicity of copper requires its complete removal prior to an application in vivo. This is an issue especially when it comes to CuAAC reactions on macromolecular structures or drug delivery systems, as copper might be retained by these systems. Thus, a quantification of the final copper content of these systems is inevitable, which we exemplified for a CuAAC reaction on liposomes using 64Cu-spiked Cu(I). In this respect, a Cu(II) nitrate solution was irradiated at the TRIGA Mark II research reactor Mainz to obtain c.a. [64Cu]Cu(II). The irradiated solution was directly used for a CuAAC on liposomes. After purification, their copper content was calculated utilizing γ-ray spectrometry. Only 0.018% of the added 64Cu-activity was still present in the liposome containing fractions after purification. This refers to a total amount of copper of 0.17 ng. The amount of retained copper is so low, that an in vivo application of the liposomes is absolutely reasonable. Besides this particular study, the experimental methodology may be applied to study many other CuAAC reactions, used for the synthesis of radiolabeled or non-radioactive species, which are intended for human applications. [ABSTRACT FROM AUTHOR]

Thorium ions exhibit unique nuclear properties with high relevance for testing symmetries of nature, and Paul traps feature an ideal experimental platform for performing high precision quantum logic spectroscopy. Loading of stable or long-lived isotopes is well-established and relies on ionization from an atomic beam. A different approach allows trapping short-lived isotopes available as alpha-decay daughters, which recoil from a thin sample of the precursor nuclide. A prominent example is the short-lived 229mTh, populated in a decay of long-lived 233U. Here, ions are provided by an external source and are decelerated to be available for trapping. Such setups offer the option to trap various isotopes and charge states of thorium. Investigating this complex procedure, we demonstrate the observation of single 232Th+ ions trapped, embedded into and sympathetically cooled via Coulomb interactions by co-trapped 40Ca+ ions. Furthermore, we discuss different options for a non-destructive identification of the sympathetically cooled thorium ions in the trap, and describe in detail our chosen experimental method, identifying mass and charge of thorium ions from the positions of calcium ions, as their fluorescence is imaged on a CCD camera. These findings are verified by means of a time-of-flight signal when extracting ions of different mass-to-charge ratio from the Paul trap and steering them into a detector. [ABSTRACT FROM AUTHOR]

229Th is the only nucleus currently under investigation for the development of a nuclear optical clock (NOC) of ultra-high accuracy. The insufficient knowledge of the first nuclear excitation energy of 229Th has so far hindered direct nuclear laser spectroscopy of thorium ions and thus the development of a NOC. Here, a nuclear laser excitation scheme is detailed, which makes use of thorium atoms instead of ions. This concept, besides potentially leading to the first nuclear laser spectroscopy, would determine the isomeric energy to 40 μeV resolution, corresponding to 10 GHz, which is a 104 times improvement compared to the current best energy constraint. This would determine the nuclear isomeric energy to a sufficient accuracy to allow for nuclear laser spectroscopy of individual thorium ions in a Paul trap and thus the development of a single-ion nuclear optical clock. [ABSTRACT FROM AUTHOR]

Sodium induces and amplifies human TH2 cell responses, potentially shaping the atopic skin microenvironment. Salting T cells' game: Sodium chloride can encourage TH17 differentiation in CD4 T cells. Matthias et al. now show that sodium chloride can also promote TH2 responses, which are central in allergic diseases. They measured effects of different concentrations of sodium chloride on memory and naïve human T cells as well as mouse cells. Collectively, higher sodium chloride enforced a TH2 transcriptional and phenotypic program. Interestingly, lesional skin from atopic dermatitis patients, but not psoriasis patients, had elevated sodium. These findings suggest that sodium chloride could be a potential player in the progression of allergy in the skin. The incidence of allergic diseases has increased over the past 50 years, likely due to environmental factors. However, the nature of these factors and the mode of action by which they induce the type 2 immune deviation characteristic of atopic diseases remain unclear. It has previously been reported that dietary sodium chloride promotes the polarization of T helper 17 (TH17) cells with implications for autoimmune diseases such as multiple sclerosis. Here, we demonstrate that sodium chloride also potently promotes TH2 cell responses on multiple regulatory levels. Sodium chloride enhanced interleukin-4 (IL-4) and IL-13 production while suppressing interferon-γ (IFN-γ) production in memory T cells. It diverted alternative T cell fates into the TH2 cell phenotype and also induced de novo TH2 cell polarization from naïve T cell precursors. Mechanistically, sodium chloride exerted its effects via the osmosensitive transcription factor NFAT5 and the kinase SGK-1, which regulated TH2 signature cytokines and master transcription factors in hyperosmolar salt conditions. The skin of patients suffering from atopic dermatitis contained elevated sodium compared to nonlesional atopic and healthy skin. These results suggest that sodium chloride represents a so far overlooked cutaneous microenvironmental checkpoint in atopic dermatitis that can induce TH2 cell responses, the orchestrators of atopic diseases. [ABSTRACT FROM AUTHOR]