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1.
Phys Rev Lett ; 123(22): 221802, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31868426

RESUMO

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.

2.
Clin Radiol ; 69(4): 363-71, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24424326

RESUMO

AIM: To validate a newly developed software prototype that automatically analyses small bowel motility by comparing it directly with manual measurement. MATERIAL AND METHODS: Forty-five patients with clinical indication for small bowel magnetic resonance imaging (MRI) were retrospectively included in this institutional review board-approved study. MRI was performed using a 1.5 T system following a standard MR-enterography protocol. Small bowel motility parameters (contractions-per-minute, luminal diameter, amplitude) were measured three times each in identical segments using the manual and the semiautomatic software-assisted method. The methods were compared for agreement, repeatability, and time needed for each measurement. All parameters were compared between the methods. RESULTS: A total of 91 small-bowel segments were analysed. No significant intra-individual difference (p > 0.05) was found for peristaltic frequencies between the methods (mean: 4.14/min manual; 4.22/min software-assisted). Amplitudes (5.14 mm; 5.57 mm) and mean lumen diameters (17.39 mm; 14.68) differed due to systematic differences in the definition of the bowel wall. Mean duration of single measurement was significantly (p < 0.01) shorter with the software (6.25 min; 1.30 min). The scattering of repeated measurements was significantly (p < 0.05) lower using the software. CONCLUSION: The software-assisted method accomplished highly reliable, fast and accurate measurement of small bowel motility. Measurement precision and duration differed significantly between the two methods in favour of the software-assisted technique.


Assuntos
Motilidade Gastrointestinal , Interpretação de Imagem Assistida por Computador , Intestino Delgado/fisiopatologia , Imageamento por Ressonância Magnética , Software , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Suíça/epidemiologia
3.
Clin Radiol ; 68(12): 1247-53, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23973163

RESUMO

AIM: To evaluate the influence of locally active Crohn's disease on systemic small-bowel motility in patients with chronic Crohn's disease compared to healthy individuals. MATERIAL AND METHODS: Fifteen healthy individuals (11 men, four women; mean age 37 years) and 20 patients with histopathologically proven active (n = 15; 10 women, 5 men; mean age 45 years) or chronic (n = 5; four women, one man; mean age 48 years) Crohn's disease were included in this institutional review board-approved, retrospective study. Magnetic resonance imaging (MRI; 1.5 T) was performed after standardized preparation. Two-dimensional (2D) cine sequences for motility acquisition were performed in apnoea (27 s). Motility assessment was performed using dedicated software in three randomly chosen areas of the small-bowel outside known Crohn's disease-affected hotspots. The main quantitative characteristics (frequency, amplitude, occlusion rate) were compared using Student's t-test and one-way analysis of variance (ANOVA). RESULTS: Three randomly chosen segments were analysed in each participant. Patients with active Crohn's disease had significantly (p < 0.05) reduced contraction frequencies (active Crohn's disease: 2.86/min; chronic: 4.14/min; healthy: 4.53/min) and luminal occlusion rates (active: 0.43; chronic: 0.70; healthy: 0.73) compared to healthy individuals and patients with chronic Crohn's disease. Contraction amplitudes were significantly reduced during active Crohn's disease (6.71 mm) compared to healthy participants (10.14 mm), but this only reached borderline significance in comparison to chronic Crohn's disease (8.87 mm). Mean bowel lumen diameter was significantly (p = 0.04) higher in patients with active Crohn's disease (16.91 mm) compared to healthy participants (14.79 mm) but not in comparison to patients with chronic Crohn's disease (13.68). CONCLUSION: The findings of the present study suggest that local inflammatory activity of small-bowel segments in patients with active Crohn's disease alters small-bowel motility in distant, non-affected segments. The motility patterns revealed reduced contraction-wave frequencies, amplitudes, and decreased luminal occlusion rates. Thus evaluation of these characteristics potentially helps to differentiate between chronic and active Crohn's disease.


Assuntos
Doença de Crohn/patologia , Motilidade Gastrointestinal , Imagem Cinética por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Doença de Crohn/diagnóstico , Doença de Crohn/fisiopatologia , Feminino , Humanos , Íleo/patologia , Íleo/fisiopatologia , Intestino Delgado/patologia , Intestino Delgado/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
4.
Neurogastroenterol Motil ; 25(6): 467-73, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23495824

RESUMO

BACKGROUND: To evaluate the correlation between the levels of C-reactive protein (CRP), calprotectin, and small bowel motility in patients with Crohn's disease assessed with MRI. METHODS: This prospective institutional review board approved study included magnetic resonance imaging enterography (MRE) and analyses of inflammatory markers in blood (C-reactive protein) and feces (calprotectin). For cine MRE, a coronal 2D-T2w sequence was used on a 1.5 T MRI system. Small bowel motility was analyzed in 13 patients using dedicated magnetic resonance MR-motility assessment software (Motasso). Contraction frequency, amplitude, amplitude diameter ratio, and luminal diameter were determined as well as the blood levels of CRP (mg L(-1) ) and fecal levels of calprotectin (ug g(-1) ). Statistics were calculated using Pearson's correlation coefficient. KEY RESULTS: A significant inverse linear correlation was found between the contraction frequency and both the level of CRP (r = -0.701, P = 0.008) and calprotectin (r = -0.805, P = 0.001). Dilatation of small bowel diameter significantly correlated with calprotectin levels (r = 0.857, P =< 0.001) but not with CRP (r = 0.447, P = 0.126). The absolute amplitude of the contractions did not correlate neither with the level of CRP (r = -0.527, P = 0.064) nor with calprotectin (r = -0.612, P = 0.026). The ratio describing the contraction amplitude relatively to the individual luminal diameter significantly correlated with calprotectin (r = 0.736, P = 0.004) and with CRP (r = 0.577, P = 0.039). CONCLUSIONS & INFERENCES: Alterations of small bowel motility during CD flares significantly correlate with the level of calprotectin and CRP indicating that they represent inflammatory activity.


Assuntos
Proteína C-Reativa/análise , Doença de Crohn/fisiopatologia , Motilidade Gastrointestinal/fisiologia , Intestino Delgado/fisiopatologia , Complexo Antígeno L1 Leucocitário/análise , Adulto , Idoso , Proteína C-Reativa/metabolismo , Doença de Crohn/metabolismo , Doença de Crohn/patologia , Fezes/química , Feminino , Humanos , Inflamação/metabolismo , Inflamação/patologia , Inflamação/fisiopatologia , Intestino Delgado/patologia , Complexo Antígeno L1 Leucocitário/metabolismo , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Índice de Gravidade de Doença
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