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1.
Phys Rev Lett ; 129(1): 011806, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35841544

ABSTRACT

We report on the direct search for cosmic relic neutrinos using data acquired during the first two science campaigns of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity molecular tritium gas source are analyzed by a high-resolution MAC-E filter around the end point at 18.57 keV. The analysis is sensitive to a local relic neutrino overdensity ratio of η<9.7×10^{10}/α (1.1×10^{11}/α) at a 90% (95%) confidence level with α=1 (0.5) for Majorana (Dirac) neutrinos. A fit of the integrated electron spectrum over a narrow interval around the end point accounting for relic neutrino captures in the tritium source reveals no significant overdensity. This work improves the results obtained by the previous neutrino mass experiments at Los Alamos and Troitsk. We furthermore update the projected final sensitivity of the KATRIN experiment to η<1×10^{10}/α at 90% confidence level, by relying on updated operational conditions.

2.
Phys Rev Lett ; 126(9): 091803, 2021 Mar 05.
Article in English | MEDLINE | ID: mdl-33750167

ABSTRACT

We report on the light sterile neutrino search from the first four-week science run of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. We consider the framework with three active neutrinos and one sterile neutrino. The analysis is sensitive to the mass, m_{4}, of the fourth mass state for m_{4}^{2}≲1000 eV^{2} and to active-to-sterile neutrino mixing down to |U_{e4}|^{2}≳2×10^{-2}. No significant spectral distortion is observed and exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results for m_{4}^{2}≲1000 eV^{2} and improve the Troitsk bound for m_{4}^{2}<30 eV^{2}. The reactor and gallium anomalies are constrained for 100<Δm_{41}^{2}<1000 eV^{2}.

3.
Phys Rev Lett ; 123(22): 221802, 2019 Nov 29.
Article in English | MEDLINE | ID: mdl-31868426

ABSTRACT

We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (-1.0_{-1.1}^{+0.9}) eV^{2}. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation.

4.
Rev Sci Instrum ; 82(1): 013303, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21280821

ABSTRACT

An electron-impact ion source based on photoelectron emission was developed for ionization of gases at pressures below 10(-4) mbar in an axial magnetic field in the order of 5 T. The ion source applies only dc fields, which makes it suitable for use in the presence of equipment sensitive to radio-frequency (RF) fields. The ion source was successfully tested under varying conditions regarding pressure, magnetic field, and magnetic-field gradient, and the results were studied with the help of simulations. The processes in the ion source are well understood, and possibilities for further optimization of generated ion currents are clarified.

5.
Med Klin (Munich) ; 96(8): 442-50, 2001 Aug 15.
Article in German | MEDLINE | ID: mdl-11560044

ABSTRACT

OBJECTIVES: Cardiovascular drugs are the most often prescribed drug class in Germany. The objective of this study is to analyze the adverse drug reaction (ADR) profiles of these drugs and to identify some targets for prevention of ADR. METHOD: Since 1997 specially trained medical staff members of five Pharmacovigilance Centers in Germany prospectively screened all hospital admissions at the departments of internal medicine of five large teaching hospitals. ADR leading to hospital admission were registered and reported. Especially ADR caused by cardiovascular drugs and all factors, which could have been important for their occurrence were analyzed. RESULTS: 559 of 2270 (24.6%) registered ADR cases were related to cardiovascular drugs. The drugs most frequently related to ADR were angiotensin inhibitors (17.9%), digitalis (17.3%), calcium channel blockers (13.9%), beta blockers (12.8%), and diuretics (12.2%). The most often observed ADR were arrhythmias (27.1%), syncopes and blood pressure dysregulations (25.1%), gastrointestinal symptoms (12.4%), and metabolic disorders (10.2%). 72% of patients were older than 65 years. Older patients were on a significantly higher number of drugs (6.2 +/- 2.4 vs 5.5 +/- 3.2; p < 0.001) than the younger ones. Furthermore, they were hospitalized significantly longer (13.2 +/- 9.9 vs 15.3 +/- 9.3 days; p < 0.01). Eleven patients (2%) died because of ADR due to cardiovascular drugs. CONCLUSIONS: Cardiovascular drugs are frequently used. They are prescribed mainly to older patients. Often observed ADR can be prevented effectively by considering their indication, by a clear definition of the therapeutic target, by a dose adjustment to the individual clinical parameters of the patient and by regular control investigations. The large number of drug-induced rhythm disorders--in particular bradycardia--show that extraordinary attention should be paid to rhythm-affecting drugs. The detailed instruction of the patient about therapeutic aims, risks and a concrete guideline for the therapy/drug handling is generally necessary.


Subject(s)
Arrhythmias, Cardiac/chemically induced , Arrhythmias, Cardiac/prevention & control , Cardiovascular Agents/adverse effects , Adrenergic beta-Antagonists/adverse effects , Adverse Drug Reaction Reporting Systems , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme Inhibitors/adverse effects , Arrhythmias, Cardiac/epidemiology , Arrhythmias, Cardiac/mortality , Calcium Channel Blockers/adverse effects , Cardiac Glycosides/adverse effects , Cardiovascular Agents/pharmacokinetics , Diuretics/adverse effects , Drug Interactions , Female , Germany/epidemiology , Humans , Incidence , Male , Retrospective Studies , Syncope/chemically induced
6.
Environ Res ; 86(2): 149-56, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11437461

ABSTRACT

This study evaluates the effectiveness of lead hazard control methods used in the Lead Hazard Control (LHC) grant program of U.S. Department of Housing and Urban Development. The LHC Program awards funds to local jurisdictions to address lead hazards in privately owned, low-income dwellings. Grantees in 14 cities, states, or counties collected environmental data in over 2600-treated dwellings making this the largest study of residential lead hazard control ever undertaken. Grantees employed a range of treatments, the most common being replacement of windows and repair of deteriorated lead-based paint. In this paper, dust lead loading levels and blood lead levels of children (6 months-6 years, if present) were observed at four periods of time (preintervention, immediate, and 6- and 12-months postintervention) in 1212 dwellings. Dust lead loading levels were also observed in a subset of these dwellings at 24- and 36-months postintervention. The geometric mean floor and window dust lead loadings declined at least 50 and 88% (P<0.0001), respectively, immediately postintervention. Three years later, floor dust lead loadings remained at or below the immediate postintervention levels. Window dust lead loadings had moderate increases, but remained substantially reduced from preintervention levels and below clearance standards. At 1 year after intervention, geometric mean age-adjusted blood lead levels had declined from 11.0 to 8.2 microg/dL, a 26% decline (P<0.0001). The LHC Program interventions produced blood lead declines similar to or greater than the percentage changes reported in earlier 1-year lead intervention studies.


Subject(s)
Child Welfare , Lead Poisoning/prevention & control , Lead/adverse effects , Manufactured Materials , Public Policy , Child , Child, Preschool , Dust , Environmental Exposure , Female , Housing , Humans , Infant , Infant, Newborn , Lead/blood , Male , Private Sector , Program Evaluation
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