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The projected sensitivity of the effective electron neutrino-mass measurement with the KATRIN experiment is below 0.3 eV (90 % CL) after 5 years of data acquisition. The sensitivity is affected by the increased rate of the background electrons from KATRIN’s main spectrometer. A special shifted-analysing-plane (SAP) configuration was developed to reduce this background by a factor of two. The complex layout of electromagnetic fields in the SAP configuration requires a robust method of estimating these fields. We present in this paper a dedicated calibration measurement of the fields using conversion electrons of gaseous 83mKr, which enables the neutrino-mass measurements in the SAP configuration.

In this work we present a keV-scale sterile-neutrino search with a low-tritium-activity data set of the KATRIN experiment, acquired in a commissioning run in 2018. KATRIN performs a spectroscopic measurement of the tritium β-decay spectrum with the main goal of directly determining the effective electron anti-neutrino mass. During this commissioning phase a lower tritium activity facilitated the measurement of a wider part of the tritium spectrum and thus the search for sterile neutrinos with a mass of up to 1.6 keV. We do not find a signal and set an exclusion limit on the sterile-to-active mixing amplitude of \\text sin² θ<5× 10⁻⁴ (95% C.L) at a mass of 0.3 keV. This result improves current laboratory-based bounds in the sterile-neutrino mass range between 0.1 and 1.0 keV.

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the effective electron (anti)-neutrino mass with a sensitivity of 0.2eV/c \\(^2\\) by precisely measuring the endpoint region of the tritium \\(\\beta \\) -decay spectrum. It uses a tandem of electrostatic spectrometers working as magnetic adiabatic collimation combined with an electrostatic (MAC-E) filters. In the space between the pre-spectrometer and the main spectrometer, creating a Penning trap is unavoidable when the superconducting magnet between the two spectrometers, biased at their respective nominal potentials, is energized. The electrons accumulated in this trap can lead to discharges, which create additional background electrons and endanger the spectrometer and detector section downstream. To counteract this problem, “electron catchers” were installed in the beamline inside the magnet bore between the two spectrometers. These catchers can be moved across the magnetic-flux tube and intercept on a sub-ms time scale the stored electrons along their magnetron motion paths. In this paper, we report on the design and the successful commissioning of the electron catchers and present results on their efficiency in reducing the experimental background.

The neutrino mass experiment KATRIN requires a stability of 3 ppm for the retarding potential at − 18.6 kV of the main spectrometer. To monitor the stability, two custom-made ultra-precise high-voltage dividers were developed and built in cooperation with the German national metrology institute Physikalisch-Technische Bundesanstalt (PTB). Until now, regular absolute calibration of the voltage dividers required bringing the equipment to the specialised metrology laboratory. Here we present a new method based on measuring the energy difference of two 83mKr conversion electron lines with the KATRIN setup, which was demonstrated during KATRIN’s commissioning measurements in July 2017. The measured scale factor M=1972.449(10) of the high-voltage divider K35 is in agreement with the last PTB calibration 4 years ago. This result demonstrates the utility of the calibration method, as well as the long-term stability of the voltage divider.

We report the results of the second measurement campaign of the Karlsruhe Tritium Neutrino (KATRIN) experiment. KATRIN probes the effective electron anti-neutrino mass, \\(m_\\), via a high-precision measurement of the tritium \\(\\)-decay spectrum close to its endpoint at \\(18.6\\,keV\\). In the second physics run presented here, the source activity was increased by a factor of 3.8 and the background was reduced by \\(25\\,\\%\\) with respect to the first campaign. A sensitivity on \\(m_\\) of \\(0.7\\,eV/c^2\\) at \\(90\\,\\%\\) confidence level (CL) was reached. This is the first sub-eV sensitivity from a direct neutrino-mass experiment. The best fit to the spectral data yields \\(m_^2 = (0.260.34)\\,eV^4/c^4\\), resulting in an upper limit of \\(m_<0.9\\,eV/c^2\\) (\\(90\\,\\%\\) CL). By combining this result with the first neutrino mass campaign, we find an upper limit of \\(m_<0.8\\,eV/c^2\\) (\\(90\\,\\%\\) CL).

In this work, we present the first spectroscopic measurements of conversion electrons originating from the decay of metastable gaseous \\(^\\mathrm{83m}\\)Kr with the Karlsruhe Tritium Neutrino (KATRIN) experiment. The results obtained in this calibration measurement represent a major commissioning milestone for the upcoming direct neutrino mass measurement with KATRIN. The successful campaign demonstrates the functionalities of the full KATRIN beamline. The KATRIN main spectrometer's excellent energy resolution of ~ 1 eV made it possible to determine the narrow K-32 and L\\(_3\\)-32 conversion electron line widths with an unprecedented precision of ~ 1 %.

ObjectiveNoisy galvanic vestibular stimulation (nGVS) has been shown to partly restore vestibular function and to stabilize stance and gait in patients with incomplete bilateral vestibulopathy (BVP). Here, we examined potential synergistic effects of nGVS when combined with standardized vestibular rehabilitation training (VRT).Methods23 patients with confirmed BVP received a 30-min vestibular rehabilitation training (VRT) program three times a week for 2 weeks. The intervention group (n = 12) was stimulated with nGVS (at individually determined optimal amplitudes) during training, whereas the control group (n = 11) received zero-amplitude nGVS (sham stimulation) during training. Outcome measurements assessed at baseline, after 2 weeks of training, and at 2-week follow-up included quantitative posturography, instrumented gait analysis, Timed Up and Go Test (TUG), Functional Gait Assessment (FGA), and clinical scores related to quality of life and balance confidence.ResultsAfter 2 weeks of VRT, all patients showed moderate improvement in balance. Irrespective of nGVS treatment, performance improved in the TUG (p < 0.013), and in the FGA (p < 0.040). Furthermore, base of support when walking with closed eyes was reduced after 2-week training (p < 0.003). Postural sway did not change. There was no difference between groups and thereby no evidence for an additional influence of nGVS on the VRT treatment effects.ConclusionnGVS does not induce synergistic treatment effects in combination with VRT in patients with BVP when applied during treatment sessions. Hence, rather than being applied in parallel, nGVS and VRT might be complementary therapeutic options with nGVS being used during postural activities in daily life, e.g., walking.

Tirzepatide, a dual incretin agonist of the glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide receptors, has favorable effects on glycemic control and body weight. The effects on cardiovascular outcomes are uncertain. We conducted an active-comparator-controlled, double-blind, noninferiority trial in which patients with type 2 diabetes and atherosclerotic cardiovascular disease were randomly assigned in a 1:1 ratio to receive a weekly subcutaneous injection of tirzepatide (up to 15 mg) or dulaglutide (1.5 mg), an agent that has been shown to reduce the incidence of cardiovascular events. The primary end point was a composite of death from cardiovascular causes, myocardial infarction, or stroke and was tested for noninferiority of tirzepatide to dulaglutide with a margin of 1.05 for the upper limit of the 95.3% confidence interval for the hazard ratio. An upper limit of less than 1.00 was considered to indicate superiority of tirzepatide to dulaglutide. A total of 13,299 patients underwent randomization; 134 were subsequently excluded because they did not meet inclusion criteria. The modified intention-to-treat population thus included 6586 patients in the tirzepatide group and 6579 in the dulaglutide group. The mean (±SD) age of the patients was 64.1±8.8 years, 29.0% were women, the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 32.6±5.5, the mean glycated hemoglobin level was 8.4±0.9%, and the mean duration of diabetes was 14.7±8.8 years. A primary end-point event occurred in 801 patients (12.2%) in the tirzepatide group and 862 (13.1%) in the dulaglutide group (hazard ratio, 0.92; 95.3% confidence interval, 0.83 to 1.01; P = 0.003 for noninferiority; P = 0.09 for superiority). The incidence of adverse events appeared to be similar in the two groups, although more gastrointestinal adverse events were observed in the tirzepatide group. Among patients with type 2 diabetes and atherosclerotic cardiovascular disease, tirzepatide was noninferior to dulaglutide with respect to a composite of death from cardiovascular causes, myocardial infarction, or stroke. (Funded by Eli Lilly; SURPASS-CVOT ClinicalTrials.gov number, NCT04255433.).