97 research outputs found
Sustained Improvements in Glucose Metabolism Late After Roux-En-Y Gastric Bypass Surgery in Patients with and Without Preoperative Diabetes
Life and death of the Bose polaron
Spectroscopic and interferometric measurements complement each other in
extracting the fundamental properties of quantum many-body systems. While
spectroscopy provides precise measurements of equilibrated energies,
interferometry can elucidate the dynamical evolution of the system. For an
impurity immersed in a bosonic medium, both are equally important for
understanding the quasiparticle physics of the Bose polaron. Here, we compare
the interferometric and spectroscopic timescales to the underlying dynamical
regimes of the impurity dynamics and the polaron lifetime, highlighting the
capability of the interferometric approach to clearly resolve polaron dynamics.
In particular, interferometric measurements of the coherence amplitude at
strong interactions reveal faster quantum dynamics at large repulsive
interaction strengths than at unitarity. These observations are in excellent
agreement with a short-time theoretical prediction including both the continuum
and the attractive polaron branch. For longer times, qualitative agreement with
a many-body theoretical prediction which includes both branches is obtained.
Moreover, the polaron energy is extracted from interferometric measurements of
the observed phase velocity in agreement with previous spectroscopic results
from weak to strong attractive interactions. Finally, the phase evolution
allows for the measurement of an energetic equilibration timescale, describing
the initial approach of the phase velocity to the polaron energy.
Theoretically, this is shown to lie within the regime of universal dynamics
revealing a fast initial evolution towards the formation of polarons. Our
results give a comprehensive picture of the many-body physics governing the
Bose polaron and thus validates the quasiparticle framework for further
studies.Comment: 9 pages, 6 figure
Blood-based biomarkers at large bowel endoscopy and prediction of future malignancies
Soluble cancer-related protein biomarker levels may be increased in subjects without findings at large bowel endoscopy performed due to symptoms associated with colorectal cancer. The present study focused on a possible association between increased biomarker levels in such subjects and subsequent development of malignant diseases. In a major study of 4,990 subjects undergoing large bowel endoscopy, 691 were without pathology and comorbidity. Plasma levels of TIMP-1, CEA, CA19-9, and YKL-40 were determined in samples collected just before endoscopy and compared with subsequent development of a malignant disease within a period of 7-8 years. The upper 90% limits of the reference levels of every single protein were used to differentiate between normal and increased levels. The levels were separated into three groups: 0, none of the biomarkers increased; 1, one biomarker increased; 2, two or more biomarkers increased. A total of 43 subjects developed a primary malignant disease in the observation period. Univariatly, increase of all four biomarkers was significantly associated with subsequent development of a malignant disease. A multivariate analysis showed that increased biomarker levels were associated with subsequent development of a malignant disease ( P = 0.002). The cumulative risk of developing malignant disease within the first 5 years after endoscopy was group 0, 3.3%; group 1, 5.8%; group 2, 7.8%. It is concluded that increased levels of plasma TIMP-1, CEA, CA19-9, and serum YKL-40 at large bowel endoscopy without findings may be associated with an increased risk of developing a subsequent malignant disease
Dietary iodine intake and urinary iodine excretion in a Danish population: effect of geography, supplements and food choice
Circulating Glucagon 1-61 Regulates Blood Glucose by Increasing Insulin Secretion and Hepatic Glucose Production
Glucagon is secreted from pancreatic a cells, and hypersecretion (hyperglucagonemia) contributes to diabetic hyperglycemia. Molecular heterogeneity in hyperglucagonemia is poorly investigated. By screening human plasma using high-resolution-proteomics, we identified several glucagon variants, among which proglucagon 1-61 (PG 1-61) appears to be the most abundant form. PG 1-61 is secreted in subjects with obesity, both before and after gastric bypass surgery, with protein and fat as the main drivers for secretion before surgery, but glucose after. Studies in hepatocytes and in b cells demonstrated that PG 1-61 dose-dependently increases levels of cAMP, through the glucagon receptor, and increases insulin secretion and protein levels of enzymes regulating glycogenolysis and gluconeogenesis. In rats, PG 1-61 increases blood glucose and plasma insulin and decreases plasma levels of amino acids in vivo. We conclude that glucagon variants, such as PG 1-61, may contribute to glucose regulation by stimulating hepatic glucose production and insulin secretion
- …