high hydrostatic pressure
Recently Published Documents

Background: High hydrostatic pressure (HHP) processing is a non-thermal method proposed as an alternative to Holder pasteurization (HoP) for the sterilization of human breast milk (BM). HHP preserves numerous milk bioactive factors that are degraded by HoP, but no data are available for milk apelin and glucagon-like peptide 1 (GLP-1), two hormones implicated in the control of glucose metabolism directly and via the gut–brain axis. This study aims to determine the effects of HoP and HHP processing on apelin and GLP-1 concentrations in BM and to test the effect of oral treatments with HoP- and HHP-BM on intestinal contractions and glucose metabolism in adult mice. Methods: Mice were treated by daily oral gavages with HoP- or HHP-BM during one week before intestinal contractions, and glucose tolerance was assessed. mRNA expression of enteric neuronal enzymes known to control intestinal contraction was measured. Results: HoP-BM displayed a reduced concentration of apelin and GLP-1, whereas HHP processing preserved these hormones close to their initial levels in raw milk. Chronic HHP-BM administration to mice increased ileal mRNA nNos expression level leading to a decrease in gut contraction associated with improved glucose tolerance. Conclusion: In comparison to HoP, HPP processing of BM preserves both apelin and GLP-1 and improves glucose tolerance by acting on gut contractions. This study reinforces previous findings demonstrating that HHP processing provides BM with a higher biological value than BM treated by HoP.

We study the effect of high hydrostatic pressure on 3D polymerized fullerite C60. We do not observe further structural changes until 150 GPa after a formation of 3D C60 under hydrostatic pressure 28 GPa. It is experimentally shown that the obtained samples consist of different clusters formed by sp3 bonds with a different set of force constants, the values of which vary within 20% and exceed the diamond force constants by the factor of 1.3–1.5. The influence of the exposure of laser radiation on the process of 3D polymerization of C60 under pressure was found. Increasing of the exposure by the factor of 15 leads to a decrease in the bulk modulus of 3D C60 from 610 GPa to 504 GPa.