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}.
Abstract
Since the discovery of neutrino oscillations, we know that neutrinos have non-zero mass. However, the absolute neutrino-mass scale remains unknown. Here we report the upper limits on ...effective electron anti-neutrino mass,
m
ν
, from the second physics run of the Karlsruhe Tritium Neutrino experiment. In this experiment,
m
ν
is probed via a high-precision measurement of the tritium
β
-decay spectrum close to its endpoint. This method is independent of any cosmological model and does not rely on assumptions whether the neutrino is a Dirac or Majorana particle. By increasing the source activity and reducing the background with respect to the first physics campaign, we reached a sensitivity on
m
ν
of 0.7 eV
c
–2
at a 90% confidence level (CL). The best fit to the spectral data yields
$${{\mbox{}}}{m}_{\nu }^{2}{{\mbox{}}}$$
m
ν
2
= (0.26 ± 0.34) eV
2
c
–4
, resulting in an upper limit of
m
ν
< 0.9 eV
c
–2
at 90% CL. By combining this result with the first neutrino-mass campaign, we find an upper limit of
m
ν
< 0.8 eV
c
–2
at 90% CL.
Abstract
Preclinical diastolic disfunction (PDD) often progresses to heart failure and distinct clinical predictors for this transformation are yet to be defined. Since deterioration of longitudinal ...strain (LS) can occur before the changes of more conventional parameters, we assumed that right ventricular free wall longitudinal strain (RVLS) might start deteriorating before the pulmonary hypertension can be established.
Methods
We followed up 243 patients (143 female) 67±9 years with PDD for 3 years. All patients had an impaired relaxation or pseudo normal transmitral patterns and E/e' 8–13 at rest, normal NT-proBNP values, and systolic pulmonary artery pressure (sPAP) ≤30 mm Hg. PDD was diagnosed by stress echocardiography (SE) if E/e' ≥13, transmittal E wave deceleration time reduction >50ms, systolic pulmonary artery pressure (sPAP) <30 mmHg, and patients remained asymptomatic during SE. RVLS as average of RV free wall 3 segments values, left atrial peak reservoir LS (LALS) as average of two LA basal segments in four chamber view and left ventricular peak systolic global LS (LVGLS) were measured by speckle tracking (ST). ST and SE was performed with 6 months intervals. 35 healthy subject served as controls.
Results
Patients with PDD had higher RVLS, LVGLS, and lower LALS compared with controls (RVLS –23.2±4.2% vs –27.3±5.1%, p<0.001; LVGLS –17.8±5.2% vs –21.9±2.8%, p<0.001; LALS 39.7±3.7% vs 44.1±4.9%, p<0.002). 76 (31.3%) patients developed sPAP increase >30 mmHg at rest or SE during follow up of which 34 (44.7%) had dyspnea. Patients with increased sPAP had higher RVLS and lower LALS values at baseline compared with the rest of PDD patients without significant differences in other parameters (RVLS –17.9±2.8% vs –24.8±3.6%, p<0.002; LALS 37.7±2.3% vs 41.5±3.6%, p<0.003; LVGLS –17.4±4.8% vs –18.2±5.1%, p>0.05). Both LALS and RVLS correlated with LA end diastolic volume index (LALS r=0.51, p<0.01; RVLS r=0.54, p<0.01). Additionally RVLS was an independent predictor of sPAP rise (OR=2.7; 95% CI=2.43–6.92; p<0.01).
Conclusion
RVLS is an independent predictor of sPAP increase in patients with PDD.
Abstract
Mitral regurgitation (MR) leads to subclinical changes that often cannot be detected by low sensitive conventional parameters and early predictors of deterioration could suggest a better ...timing for intervention.
Methods
We follow up 175 asymptomatic patients 56±13 years (79 female) with severe primary MR in sinus rhythm and without diabetes mellitus and renal disease for 2 years. Global longitudinal strain (LS) of left ventricle (LVGLS), right ventricular (RV) free wall LS (RVLS), and left atrial (LA) peak reservoir LS as average of two basal segments in 4 chamber view were measured by speckle tracking along with indexes of LV end-systolic and end-diastolic volumes, LV ejection fraction (EF), left atrial end-systolic volume index (LAVi) every 6 months. Normal reference values of LS were obtained from age and sex matched 40 healthy controls.
Results
Patients with MR had higher LV ejection fraction (EF), LVGLS, LALS and lower values of RVLS compared with controls (EF 67.4±5% vs 59.3±4%, p<0.05; LVGLS –25.2±2.3% vs –21.2±1.9%, p<0.03; LALS 46.2±5.1% vs 42.4±3.7%, p<0.04; RVLS –23.4±5.1% vs –27.3±2.8%, p<0.03). 53 (30%) patients developed symptoms at exercise during follow up. Symptomatic patients at baseline had higher values of RVLS compared with patients who remained asymptomatic during follow up without significant differences in EF, LVGLS, LALS (RVLS –21.4±2.6% vs –25.8±3.2%, p<0.02; EF 66.8±2.4% vs 68.1±3.1%, p>0.05; LVGLS –24.8±2.1% vs –25.3±2.3%, p>0.05; LALS 45.7±4.1% vs 46.5±4.4%, p>0.05). RVLS correlated with LAVi (r=0.53, p<0.01) and LALS (r=0.57, p<0.01). Regression analysis defined RVLS as an independent predictor of symptoms development (OR=3.2; 95% CI=1.37–7.63; p<0.01).
Conclusion
RV longitudinal strain predicts symptoms in patients with chronic primary mitral regurgitation.
Abstract
Left atrial (LA) dimensions, wall composition and function strongly depend on left ventricular (LV) diastolic function and impaired in patients with preclinical diastolic disfunction (PDD), ...which increases the likelihood of atrial fibrillation (AF) occurrence. LA longitudinal strain (LALS) is a sensitive parameter of subclinical myocardial changes and its reduction might be predictive for AF.
Methods
168 patients (90 female) 68±9 years with arterial hypertension in sinus rhythm with preserved systolic function (LVEF>50%) and PDD and without renal or valvular disease and 45 age and sex matched healthy controls were followed up for 2 years. PDD was diagnosed at stress echocardiography (SE) if E/e' ≥13, transmittal E wave deceleration time reduction >50ms, systolic pulmonary artery pressure (sPAP) >30 mmHg, and patients remained asymptomatic. LALS was measured by speckle tracking echocardiography as average value of two basal segments in 4 chamber view along with LA end-systolic volume index (LAVi), LA EF, LV mass index (LVMi), and LVLS. 72 hours Holter monitoring was performed every 6 months.
Results
Patients with PDD had larger LAVi, less LALS, higher LVLS and bigger LVMi compared with controls (LAVi 30.5±4.9 ml/m2 vs 23.1±4.8 ml/m2, p<0.001; LALS 34.7±6.9% vs 45±4.3%, p<0.001; LVLS –17.4±2.4% vs –20.8±2.1%, p<0.002; LVMi 81.8±12.3 g/m2 vs 68±9.2 g/m2, p<0.001). AF was registered in 42 (25%) patients with PDD. LAVi, LVLS and LVMi did not significantly differ in PDD patients with or without incidents of AF however LALS was significantly less in patients with AF (26.8±7.5% vs 37.2±8.1%, p<0.01). Multivariate analysis defined LALS as an independent predictor of AF development (OR=2.4; 95% CI=2.41–5.96; p<0.01) with the cut-off value of 28.9%.
Conclusion
LA peak reservoir LS is an independent predictor of AF development in patients with PDD.
Cerebellar injury is an important complication of preterm birth with far-reaching neuropsychiatric sequelae. We have previously shown a significant association between isolated injury to the ...premature cerebellum and subsequent impairment of regional volumetric growth in the contralateral cerebrum. In the current study, we examine the relationship between these remote regional impairments of cerebral volumetric growth and domain-specific functional deficits in these children. In 40 ex-preterm infants with isolated cerebellar injury, we performed neurodevelopmental evaluations and quantitative magnetic resonance imaging (MRI) studies at a mean age of 34 months. We measured cortical gray matter volumes in 8 parcellated regions of each cerebral hemisphere, as well as right and left cerebellar volumes. We show highly significant associations between early signs of autism and dorsolateral prefrontal cortex volume (P < 0.001); gross motor scores and sensorimotor cortical volumes (P < 0.001); and cognitive and expressive language scores and premotor and mid-temporal cortical volumes (P < 0.001). By multivariate analyses, each unit increase in the corresponding regional cerebral volume was associated with lower odds of abnormal outcome score, adjusted for age at MRI and contralateral cerebellar volume. This is the first report linking secondary impairment of remote cerebral cortical growth and functional disabilities in survivors of prematurity-related cerebellar brain injury.
PDF
